Hey guys, I just made a groovy new friend – HeavyPetal.com is a great blog on gardening that has a fun tongue and cheek way of informing growers on new and interesting grow techniques, I strongly suggest you check them out!

Australians have a passion for both hydroponics and greenhouses, and they both come together perfectly in this new resource. Practical Hydroponics and Greenhouses @ hydroponics.com.au has a ton of great info and is  put together really well. (Thanks to Dan and Everest at UrbanGardenMag for to hook up) Refreshing point of views from across the globe, giving us another place to read and learn from, a slightly different slant with fresh info varying from the US.

Hey guys, hope you all had an incredible holiday! We all came in today rested and happy, and I was greeted by an email from the Indoor Gardener Magazine. I am proud to announce that I have my first Published article in a grow mag… YIPPY. You can DOWNLOAD THE ISSUE HERE. I’m super proud to have written the article they used for the PGS blog and I look forward to another year of intense plant science and research here at PGS. Thank you to all our supporters who leave cool comments and questions, keep em coming!

Lost in a sea of plastic trays …

I spotted them as soon as they came in through the door of the growshop.  This couple weren’t just browsing.  To me it was obvious that this was their first time in a hydroponics store.  I watched them eye up the seemingly endless array of nutrients, additives, powders and other plant products.  Then they spied the plastic trays stacked up next to the grow tents.  They looked them up and down with evaluative frowns, and finally they continued to the pipettes, propagators, pumps, sheeting, ducting, fans, filters, lights, reflectors … well, you know … the whole shebang you see in any growshop really!

Eventually, they made their way to the counter looking a bit overwhelmed.

“I want to start growing hydroponic”, began the young gentleman.

“Well you’re in the right place!”, my chirpy salesman friend responded sipping a well brewed cup of coffee.  The chap gestured a half spin around to glance at the store again and, turning back, asked a very simple question: “Where do I start?”

Q. What plants can be grown in a hydroponics system?
A. Anything that can be grown in soil can be grown hydroponically.  Flowers, herbs, vegetables, fruit trees, and ornamental shrubs.  You name it!

Where to start?

The hydroponics store can be a daunting place for a newcomer.  With all the aforementioned peripheral products on show (often specific to growing indoors) the core simplicity of hydroponics can all too easily be lost.

So, for now, forget about growroom design.  Forget about lights, fans, ducting, and all that.  Hydroponics is none of these things. Hydroponics is simply growing without soil. If you want to start thinking about growing hydroponically, the logical place to start is by taking a look at the different types of hydroponic systems available.  All hydroponic systems are trying to do the same thing.  That is – to provide oxygen, water and nutrients to your plants’ roots, these (along with light) are the essential core elements that your plants need to grow and flourish. Whether you are growing indoors using supplementary lighting, or in a greenhouse, the science of hydroponics remains the same.

Fundamentally, hydroponics is very simple and there are lots of easy to use and affordable systems out there to help you achieve brilliant results.

Why different systems?

Why not?  We don’t all drive the same car do we?  All systems have their pros and cons.  Some are small, good value for money and easy to use – but don’t permit much scope for fine tuning or up-scaling.  Some systems are suited to particular applications (such as one or two large plants) whereas others can also adapt to growing larger numbers of small plants too.  Some systems are more expensive and have plenty of scope for tweaking, but inherently there’s more potential for things to go wrong.

As well as asking yourself questions about the space you have available, make sure you ask yourself a few more of these practical questions:

• How much time will you have to spend with your plants?
• Will you often be leaving them unattended for more than a night or two?
• How confident are you in your own DIY abilities?
• How many flights of stairs would you have to haul 50 litre bags of growing medium up (if you were to choose a system which required it?)
• Does the space in which you want to grow suffer ever from extreme temperatures?  (I’m thinking specifically of attics here)
• How much space do you have for a nutrient tank?
• How important is it for the system to operate quietly?

Hydroponics in a nutshell

The word “Hydroponics” comes from Greek, “hydro-ponos”.  Literally it can be translated as “water (hydro) at work”.  So what “work” is the water doing?  Well, as it happens, quite a bit actually!  Hydroponic plants are not grown in soil. Instead all the nutrients they need are supplied directly from the water.  This is achieved by first dissolving special hydroponic nutrients into the water – the resulting “mix” is often referred to as a nutrient solution.  It contains all the essential food in a directly accessible form – food which a plant would usually have to search for in soil by creating an extensive root system.

Hydroponics:  Pros and Cons

The advantages of hydroponics include:

• Higher yields
• Increased growth rates
• More control over nutrient and water levels
• Maintenance involves less labour
• Soil borne diseases are virtually eliminated
• A sterile growing environment avoids soil borne pests
• While removing soil-grown crops from the ground effectively kills them, hydroponically grown crops such as lettuce can be packaged and sold while still alive, greatly increasing the length of freshness once purchased
• Fewer pesticides are required
• Edible crops are not contaminated with soil
• Water use can be substantially less than with outdoor irrigation of soil-grown crops
• Many hydroponic systems give the plants more nutrition while at the same time using less energy and space
• It provides the plant with balanced nutrition because the essential nutrients are dissolved into the water-soluble nutrient solution

Of course there are some down points:

• Higher set up cost than just buying some soil and pots although yield benefits make this worthwhile
• Less margin for error
• Recirculating hydroponic systems (those which pass the same nutrient solution over the roots more than once) can spread disease between plants. Nothing to do with hydro, I problem common will all growing
• If timers or electric pumps fail or the system clogs or springs a leak, it can spell disaster for your crop so it’s important not to buy the cheapest pumps and timers

How does hydroponics give higher yields?

Hydroponic growing media is lighter than soil so it allows roots more access to oxygen and a better flow of water and nutrients  and all this helps to stimulate root growth. Plants with ample oxygen in the root system also absorb nutrients faster. The nutrients in a hydroponic system are mixed with the water and sent directly to the root system so the plant does not have to expend energy searching in the soil for the nutrients that it requires.  The hydroponic plant requires very little energy to find and break down food. The plant can then invest this extra energy to grow faster and to produce more fruit.

Active vs. Passive

Before we talk about specific types of hydroponic systems, it’s useful to explain a few ‘core’ principles to help us distinguish between them.

You may have heard of “active” and “passive” systems.

An active hydroponic system is labour saving and automatically provides plants with water and nutrients much more frequently than is possible with manual feeding. Active hydroponic systems actively move the nutrient solution, typically using a pump.  In active systems more nutrient solution is passed over the root-zone than the plants actually take up.  Active hydroponics is a bit like dining at one of those conveyer belt sushi bars with those endless little nibbles going round and round.  Lots more food is presented than you can actually eat!  (Unless you’re a fat bastard.)  You just take what you want when you need it, but the more frequently the roots have opportunity to take up nutrient solution the more nutrient solution they will be able to take up and the bigger the yields will be.  The roots are able to take up much more nutrient solution than if they were manually fed just a few times per day – and this results in higher yields. In the last thirty years the technique has become the main commercial growing technique.

Q.    What do you mean by “growth media”?
A.    Growth media, growing media, medium, substrate … it’s all amounts to the same thing.  Some hydroponic systems need a substitute for soil so that the plant has ‘something’ to actually grow in – to keep it sturdy for one thing – but also to absorb nutrients for the roots to take up.

Restrictive and non-restrictive growth media

In order for active hydroponics systems to work effectively, the flow of nutrients must not be restricted by overly absorbent growing media – otherwise things would get very soggy and oxygen starved.  NFT uses very little medium – most commonly 3 or 4” cube but if you’ve got good  plant support you can just use a 1” propagation cube. Coco fibre is a restrictive media.  It absorbs nutrient solution into itself rather than letting most of it merely flow through it like clay pebbles.

Hydroponics at its simplest:  Passive hydroponics using pots

With passive hydroponics the plants are grown without soil but the grower has to decide what quantity of water and nutrient and in what ratio the plants should be fed.   The simplest example of passive hydroponics is hand-watering your plants in pots of coco fibre.  This is the most basic way of growing hydroponically – ideal for beginners.  If you don’t mind the added labour of watering your plants regularly, and you are happy to guess how much water and nutrients to feed your plants then it’s an attractive and cheap option, although yield increases won’t be anywhere near as large as in an active hydroponic system.

Water your plants little and often.  Sit every pot in its own deep saucer.  Once they are well established in their pots you can supply nutrients solution by watering the saucer, rather than the top of the pot. The growing medium will suck the nutrient solution upwards through capillary action and keep a moist, yet aerated environment around the roots. Remember, moisture, nutrients and air is the winning root-zone combination.  A lot of growers feed their plants by watering from the top –this isn’t ideal for established plants.

The size of your pots should reflect the desired finishing size of your plants.  A 3 – 5 litre pot is fine for a maturing a cutting that has had little or no vegetative growth since rooting.  Whereas a 10 or 15 litre pot can accommodate a much larger plant that has enjoyed a lengthy vegetative period of four to six weeks or more.  Obviously these are just ‘rules of thumb’.  You will have to experiment for yourself with your own particular plants and varieties and see which works best for you.

Recirculate or run-to-waste?

As well as considering hydroponics systems as “active” or “passive”, they are often divided into two alternative categories:  Recirculating and run-to-waste.

When a hydroponic system is described as “run-to-waste” it means that any excess nutrient solution that has drained from the root-zone is not used again.  It is usually collected in a waste tank to be disposed of later.  This means that the nutrient solution is only ever used once.

In recirculating systems (Ebb and Flow, NFT) any excess nutrient solution is fed back into the nutrient reservoir to be ‘recycled’.  You will need to keep an eye on rising pH and nutrient strength in your reservoir as this will tend to fluctuate (over a period of time not straight away).  Many growers top their reservoirs up with water every few days and adjust the pH back to optimum levels at the same time.  The larger your nutrient reservoir, the less your susceptibility to changes in conductivity and pH.  Depending on the size of the nutrient reservoir, it’s advisable to completely change its contents with freshly made nutrient solution every one or two weeks for most hobbyist applications -

Recirculating systems allow you to pass more nutrient solution over your roots because you don’t have to worry about waste.  They use non-restrictive mediums (or no medium at all).

Let’s take a look at a popular type of recirculating system:

The Ebb and Flow System (aka Flood and Drain)

The Ebb and Flow system is particularly popular with growers who want to change feeding schedules throughout the plants lifecycle, especially those cultivating mother plants. It uses a submersible pump in the nutrient reservoir to pump nutrients into an upper tray containing the plants.  The theory of “flood and drain” is very simple:  When the pump is switched on, the nutrient solution is pumped up to the upper tray and it floods the root system, getting rid of any old air that was in the root-zone.  Once the nutrient solution has reached the maximum level, it starts to drain back into the reservoir via an overflow pipe.  As the nutrient solution drains back down into the reservoir, the root-zone takes in a fresh supply of oxygen rich air and stale air is pushed out.

More oxygen = increased metabolic rate = increased nutrient intake = more growth!

Clay pebbles are often used in ebb and flow systems.  The tray is filled with pebbles and young plants grown up in rockwool cubes are inserted into the pebbles once roots start showing.

Some gardeners in the UK grow their plants in pots filled with coco coir and clay pebbles, or a mixture of small chunks of rockwool and clay pebbles, and sit these pots in the flood tray – the capillary action of the roots take up the nutrients they need in a similar way to the passive pot hydroponics method described earlier.

Active Ebb and Flow is a low maintenance hydroponics solution, which offers growers more control and great results are possible.  Two key factors to get right are the automatic flood times and flood frequency.

When working out how long to flood for, remember the extra time it takes for the nutrients to drain back into the reservoir.  Ideally, you won’t want to be using a standard 15 minute segmental timer to control your pump as fifteen minutes (plus drainage time) is too long for the root-zone to be without oxygen – a negative to basic ebb and floods.  Obviously flood times will vary depending on the size and exact type of the system you are using, but as a general rule of thumb, once the nutrients have flooded to their maximum level (delimited by some form of overflow drainage mechanism that will be incorporated into the system) then it’s time to stop pumping.   All good Ebb and Flow systems will come already supplied with the correct type of pump – one that allows the nutrient solution to drain back through it.

The required flood frequency will increase as your plants mature and their nutrient requirements increase.  During the early stages, one flood a day might be sufficient.  Whereas, towards the end of flowering period your plants may require four or more floods a day.  Also, consider what medium you are using.  How much does it absorb the nutrient solution?  A restrictive medium like coco coir will need a lot fewer floods than clay pebbles, for example.

Ebb and flow moves a lot of water around.  It may sound like an obvious thing to say but just make sure the reservoir is sturdy and fit for purpose.  A couple of friends of mine were growing in an attic using a huge old second-hand nutrient tank which had two trays sat on top of it rather than one.  They hadn’t noticed that it was already a little warped.  During the flood cycle, the weight of top trays caused the tank below to crack and …… the rest of the story is very wet indeed…

Ebb and flow systems are not always based on a grow tray.  Some ebb and flow systems work by connecting a series of special pots to a reservoir tank.  (Often referred to as a ‘multipot’ system).  The nutrient solution is pumped to each pot via a network of hosing.  Each pot acts like its very own mini flood and drain system.  Plants sit in an upper pot, which sits on a slightly larger lower pot.  Nutrients are pumped into the lower pot – the base of the upper pot is perforated so that the plant roots can feed.

There are several different types of ‘multipot’ systems on the market.  Consider the number and size of the plants you wish to grow and measure this against the size of the pots used by the system you are considering.  In the early stages when your plants’ root systems are minimal, be sure that the flood height achieved by the system actually meets their roots.  Otherwise, you can help things along a bit by hand watering for a few days.  It’s also worth ensuring that your multipot system drains as well as it floods.  Often it’s possible to make a few simple tweaks to optimise any given system for your particular environment – such as raising the plants up a few inches higher on a platform, so that gravity helps drain any run-off nutrients out of the pipe work and back into the reservoir.

Various systems are available as 4, 6, 12, 24, 36, or 48 pot systems.

Nutrient Film Technique (NFT)

The Nutrient Film Technique or NFT is also known as a ‘pure water culture’ technique insofar as the plants’ roots are not grown in any solid medium such as coco.  Although saying that, many growers start their plants off in rockwool cubes, and then sit them within an NFT system.  The roots are contained in a plastic trough or tube through which nutrient solution is constantly circulated.

NFT is probably the most popular hydroponic growing method in the UK with Nutriculture’s GroTank being the first commercially produced active hydroponic system on the market back in 1979. It produces huge yields by ensuring that the roots have constant – rather than just frequent – access to water, nutrients and oxygen.

As implied by the name, the depth of the nutrient stream is very shallow – just a couple of millimetres.  This is to make sure that the roots have lots of access to oxygen.

So how do you create this “nutrient film”?  Well, first of all the nutrients are pumped from the reservoir into the trough where the roots are sitting.

The bottom of the trough needs to be inclined at a very slight angle.  Nutrient solution enters the trough at the top of the incline, and gravity pulls the nutrients along the trough.  The run-off nutrient solution then re-enters the reservoir. Modern systems use special pumps which aerate the nutrient solution

NFT gives tremendous results.  It is the arguably the easiest active hydroponic method to use because there are no watering schedules to calculate – once you are set up you just check pH levels and keep the tank topped-up. The plants just take what they need, when they need it and whatever they don’t need flows away so there is no chance of under-watering or over-watering – the biggest challenges facing growers.

It is important not to buy a cheap pump because if the pump fails plants can dry up quickly in an NFT system as there is no growing medium surrounding the roots to provide a fall-back, although the capillary matting provides some safeguard.  One of the great things about NFT is the lack of growing medium, although  this means there is less natural insulation around the roots to provide protection against extremes in temperature.  So an NFT system with a thermostatically controlled heater is a good option.

NFT systems come in all shapes and sizes from 70cms long to a whopping 3metre long – there’s an NFT system for everyone.

Dripper Irrigation

A Recirculating Dripper System.

A dripper system can either be recirculating or run-to-waste.  Nutrient solution is fed from the reservoir via a pump along some piping.  This piping sometimes terminates in a “dipper ring” where it typically feeds one plant, or it splits off (usually via an adaptor) into several narrower pipes and into “dripper spikes” to feed multiple plants.  These spikes are inserted into the growing medium by each plant site.  Nutrient solution drips out of the dripper spike and into the growing medium.  Adjustable dripper spikes allow you to individually adjust the drip rate to each plant.  Any excess nutrient solution needs to be fed either back into the nutrient solution (recirculating) or to a waste point (run-to-waste).

Many active hydro drip irrigation systems offer the precision and control of hydroponic feeding combined with the flexibility of growing in pots.

Pots are placed on a support tray that rests on a nutrient tank and periodically nutrient solution is delivered to each plant through a dripper to each pot. So for those of you who prefer to grow in pots this method spares you the hours and hours needed to manually feed. If you don’t want to grow the number of plants supplied with a particular system you can simply remove some of the pots!

You can find systems in various sizes (4, 8, 10, 16, and 20 pot systems) – make sure you check that the dripper supplied are compatible with the media you want to grow in.  Some manufacturers generous supply a range of drippers to suit different media.

Another great example of a self-contained recirculating dripper system is the Aquafarm and Waterfarm by General Hydroponics.  Both systems work on the same principle – they differ only in size and price. Plants are grown within a chamber filled with clay pebbles. The growing chamber is suspended above a reservoir filled with nutrient-enriched water. An air pump drives the nutrient solution up through the “pumping column”, to the drip-ring, where it then drips down through clay pebbles. This infuses the nutrient with oxygen and constantly bathes the roots. .

Some growers increase the diameter of the drainage holes in the top pot first to allow the root systems more space!

Remember, as with all recirculating systems, keep an eye on rising CF and fluctuating pH and change the nutrient solution regularly.

Low pressure sprinkler / droplet systems

Amazingly, it’s possible to grow plants in air!  Often these systems are referred to as ‘aeroponic’ because the plants are fed via a nutrient mist.  The plants are secured (typically via net pots) at the top of the system and their roots dangle down into a lightproof box.  Inside the box, a submersible pump is used to push the nutrient solution through atomisers, creating a mist.  The idea is that the roots have increased oxygenation, of course, which speeds up growth.

As with NFT, there’s no media to speak of really – other than maybe something to start them off in.  Great insofar as there’s not sack after sack of medium to dispose of afterwards – but remember to keep an eye on ambient temperatures.

High pressure fine mist systems (True aeroponics)

True aeroponics is achieved when plants are fed via a fine nutrient mist.  High pressure and air compressors are used to create the optimum sized particles for liquid and oxygen feeding 100% of the time.  In the past there have been problems creating this mist due to clogged atomisers.  In the last issue of UGM we featured the Atomix – a British made true aeroponic system that has overcome these problems with state-of-the-art atomising technology.

Hopefully as well as expanding your knowledge on the types of hydroponic systems available, and the vocabulary that is used to describe them, you’ll be better able to make the right choice for your own particular circumstances.   There are probably as many different ways to grow as there are growers!  If you’re a beginner, my advice is keep things modest and simple from the offset – experiment with different ideas in your growroom and circle of friends.  It’s not about saying which hydroponic system is the best – more, which one works best for you.

Well, that’ll do for now!  We’ll be covering lots more systems in a whole lot more detail in future issues, as well as a few that we left out for brevity’s sake!

Thanks to UrbanGardenMagazine for the article Original Page Here

Simon Hart from Grotek takes a detailed look at the all-important flowering phase and deciphers what’s really going on inside those buds and blooms.

In Canada as in the UK we experience seasonal changes and many outdoor growers who get down and dirty outdoors take flowering and fruit development for granted.  It is true that photoperiod change is a major contributor to the success of most crops’ success, and full credit to the sun for helping out!  But science is giving us insight into working with light to supercharge the flowering process together with the supplements we add.

The key question is:  What is going on inside your flower crop, and how can you work with your light source to accelerate the process and achieve the best yield possible?

Although the contents of this article could apply to outdoor growing from the summer solstice through the autumn, most urban gardeners don’t have much outdoor space and have taken their activities indoors.  In an indoor setting the photoperiod is changed manually by adjusting your light timer setting and shortening the length of your light cycle.

There are many options available for flower production and the choice can be quite overwhelming in your local growshop.  First and foremost, look to the shop owner for guidance – but even after you’ve heard their advice you must test what premium products are doing for you, and whether they’re providing the benefits you’re looking for.

Techniques for triggering flowering

When triggering flower development it is important to plan for your plants’ success.  Make sure you are transitioning your fertiliser levels properly to provide your crop with the best opportunity possible.  For example, a quick foliar spray of kelp meal a week before flowering can provide key signals to developing sites increasing cell division, promoting lateral branching and relieving some of the stress associated with initiating blooming.

There is also an emerging group of products based around this transition stage meant to stimulate key reactions within the plant, forcing it to increase flower site development.  By adding these products before flowering and into the initial flowering stage you can achieve a noticeable and positive change in flower development.  I know several people that are now adding these products but are also experimenting with a more gradual photoperiod change.

Outdoors the natural cycle of seasonal change is slow and flowering is induced over several weeks.  Some experienced growers are now toying with their light cycle by adding 7 to 10 days to a plant’s flower cycle and adjusting the light cycle by an hour every couple of days.  Initial results have shown that if you have extra days to play with you can decrease the internodal stretching, keeping your plants a little more compact.  This could be a result of providing your plant the additional time to adapt and change certain chemical reactions during this transitional phase.

Primary Nutrients

Primary nutrients are essential for plant growth and development, especially during the flowering stage where plants are forced to expend a staggering amount of energy.  Nitrogen, Phosphorous and Potassium all play a vital role in this amazing transformation.

Nitrogen

Upon entering the plant most nitrogen will be worked into the chloroplast where it is a key component to the formation of chlorophyll. Although nitrogen is exceptionally important in vegetative growth it is also a key to successful flowering at a lower level.  Nitrogen is essential in the formation of proteins and amino acids which can have serious effects on flower development.

Phosphorous

Develops a larger root system to feed flowers and is involved in the Kreb Cycle and the Calvin Benson cycle, essential for energy production and energy movement within the plant.  No phosphorous = no carbohydrates.

Potassium

Assists with chlorophyll production, starch formation and the movement of those sugars to the flowering sites.

Secondary Nutrients

Secondary Nutrients can be a lynch pin for success, as many nutrient deficiencies during a flowering period are related to the mobility of secondary elements.
Calcium is a backbone for cellular structure, and is very important for heavy flowering plants to reduce weight related stress.  Calcium is immobile once set in the plant so adding calcium throughout flowering is very important.

Magnesium is a co-factor in enzyme reactions and essential to chlorophyll production. It is a key to a flowering plant’s success.

Sulfur works to increase proteins and oil development while building vitamins and amino acids.

Micronutrients

Micronutrients are those elements required by plants in microscopic amounts.  But don’t underestimate their importance!  Many of them play a critical role in developing amino acids and propelling rapid photosynthesis.  Although these compounds are important to flowering I’ll save their discussion for a future article.  All good quality nutrients should be providing all necessary micronutrients.

Co Factor Elements

Co factor elements are a fairly new consideration in high tech flower production.  These elements are not considered essential for plant growth but they have been shown to influence reactions involving other elements, and provide additional benefits to the plants.  There are several elements that have been studied including: Cobalt (Co), Silicone (Si), Nickel (Ni) and Vanadium (V).  There are also ongoing studies on at least 10 other elements, which show some type of benefit to the plant.  There is also the concept of biological transmutation, but again, this is definitely a story for another day!

Synthetic or natural chelates?

Synthetic or natural chelates can be very important for nutrient availability and uptake within the plant.  Chelates form a bond with an element.  This bond or coating helps the molecule become more available to the plant (easier to absorb).  Synthetic chelates are generally used with micro nutrients such as iron and can be seen on the label expressed as EDTA, DPTA and others.  Caution should be used with synthetic chelates which can be phytotoxic at higher levels.  Natural chelates are found in humic acid, fulvic acid and in some forms of amino acids.  Humic and fulvic acid are both derived from leonardite coal which is a type of shale rich in hydrocarbons.  These extractions can seriously affect the rate of growth in plants and can be used in all stages of development.  A good rule of thumb is to use humic in soil and soiless situations which have a more neutral pH and fulvic acid in water culture where pH is generally slightly more acidic.  Fulvic acid is also a must for any foliar spray as it helps with nutrient rich spray being absorbed through the leaves.
Natural chelates are excellent for pumping more nutrition into your plants and stimulating microbial activity in your medium but because they are a carbon based molecule they also effectively add more carbohydrates (sugars) as they cycle through the plant.  Some veteran gardeners even recommend foliar spraying fulvic acid during late flowering on oil producing flowers to increase oil content and also induce a more fragrant aroma.  I’m not sure I endorse foliar spraying plants late in a flowering cycle but the gardener is always right!

Carbohydrates

Carbohydrates are the basis for most life on earth and are the basis for energy in all plants.  Carbohydrates are formed from carbon, hydrogen, and oxygen.  The photosynthesis reaction uses the sun’s energy to bind the three elements into sugars. Monosaccharides are simple sugar for fast conversion (glucose), while disaccharides are still fairly easy to convert(sucrose).  Polysaccharides are groups of sugars that from more complex bonds such as starches and cellulose.   Adding in carbohydrates during flowering can provide critical energy for your plants to supplement internal production.. As with many other topics discussed in this article this is a vast topic that will need a closer look in future write ups.

Enzymes

Enzymes are created by nearly all living creatures, including plants, using energy reserves from metabolism.  Supplementing with a high quality enzyme can provide a great insurance policy for important crops.  Good quality enzymes can be an expensive purchase and are not for indiscriminant use but under the right circumstances they are worth their weight in gold.  During the flowering cycle the primary function of enzymes would be to “clean up” the medium by decomposing organic waste.  This reduces the likelihood of developing a root based pathogen problem (ex. Pythium).  While keeping your medium clean a quality enzyme supplement will also be breaking down cellulose (polysaccharides) from dead root material, which will decompose into useful carbohydrates (monosaccharides) these will be reabsorbed into your plant providing additional sugar energy during peak flowering.  The three broad groups of enzymes used by plants are cellulose, protease, and amylase which break down cellulose, proteins and starches.

You are at the cutting edge!

The science found in some of the products on the shelf in hobby stores is virtually on the cutting edge of technology.  As an urban gardener it is up to you to test these products in your own garden and determine whether the benefits are worth the price-tag.  Remember that every plant and every situation is different so by testing various products you are working to improve your own success.  Always return the favour to the store owner that offered advice by giving them the feedback from your trials to pass along to other curious gardeners.  Now get back to growing!

Simon Hart is the senior technical advisor for Grotek Manufacturing in Canada.  If you have any questions regarding flowering or anything else garden related you can email Simon at simonh@grotek.net

Thanks to urbangardenmagazine for the article – Original Page Here

Summer is  upon us.  And most  indoor gardeners, unlike their outdoor counterparts, are hoping for a poor one.  A hot summer usually means hot growrooms.  High temperatures in your growroom can devastate the quality and quantity of your crop.  Plants ‘survive’ rather than thrive.  Some growers even shut down their operations all together preferring to reserve their energies for later in the year.  But there are many ways to counteract rising temperatures, as Everest Fernandez explains:

48 degrees Celsius.  It’s roughly the temperature of my oven when I warm some plates.  You can also experience this heat by visiting Delhi in May.  Unbelievably, it was also the maximum temperature recorded in my friend’s growroom a few years ago.  Despite a generous watering the day before, the vast majority of his plants had wilted, most likely cursing him as they shrivelled.  Featherlight pots, frazzled, crisp leaves…  it was all a very sorry sight.  Tragically they were six weeks into flowering and it all ended right there and then.  The yield was poor.  And the quality was  … embarrassing.

What had gone wrong?  Well, everything really.  It was the first time my friend had ever grown in a loft and he didn’t fully appreciate that un-insulated roof space is particularly susceptible to extremes in temperature.  i.e. in the winter it can get very cold, and in the summer it can become like a furnace.  Whereas I was smugly enjoying fairly uniform temperatures all year round in my cellar.

My friend’s attic set-up was overly simplistic – mainly due to his resistance against parting with much cash.  Fifty or so plants in ten litre pots were relying on on “natural ventilation”, as he put it, from the eaves.  Yes, that’s right, just a few oscillating fans were shifting the air around with no artificially created inflowing air and no extraction!  Now add 3,200 watts of light to this monstrous equation, a Great British heatwave, mix liberally with inexperience and downright stupidity, and the result?  I could actually smell the plants cooking when I opened the loft hatch…

Ok, enough extreme examples!  But what does ‘too hot’ actually mean in botanical terms?

Everest’s Hot Grow Room Rule Of Thumb

If it’s uncomfortable for you to be in your growroom, then it’s highly likely that it’s uncomfortable for your plants too.  So, if you find yourself ripping off you t-shirt (grrrr!) after a few minutes of plant-tending and drying your sweaty pits infront of a fan then let this be a clear signal to you that you have a heat problem!

When temperatures are high more water (in the medium) is lost to evaporation. If the nutrients are then too concentrated in the drying medium the roots will burn and the leaves droop and may be lost altogether. When temperatures rise above a certain level plants effectively shut down photosynthesis and just concentrate on surviving, rather than focusing on growth or flower development. Damage will not be obvious but the delay to production will be. High temperatures can also cause some plants to ‘stretch’ and become leggy. Deadly root diseases like pythium thrive in high temperatures.

Everest’s Ideal Growroom Temperature

I’m happiest when the maximum temperature in my growroom is around 25 to 27 degrees Celsius. 28-32 degrees celsius is tolerated but is not ideal. I measure this temperature by placing a probe in a shaded spot in amongst the plants.  I like my minimum temperature to be around 15-18 degrees Celsius.

Heat Problems And Growroom Solutions.

Ok so we’ve established excess heat as our enemy.  If you grow plants for essential oils then you should be particularly vigilant against high temperatures – ideally you should be looking for a 10 degrees Celcius difference between your daytime and nightime temperatures.

Ambient Temperature (i.e. the actual temperature outside)

It may sound a bit obvious, but it’s worth pointing out:  If it’s hot outside it’s going to be hot inside.  Make sure your lights come on at night when outside temperatures are cooler.  Consider a shorter cycle (eg. 10 hours on, 14 hours off) to speed things up a bit.  Keep inflow and extractors on 24/7 – plants are still busy developing at night and enjoy fresh air during this time too.  Try to take air from a cool room in the house or an outside vent in a shady area. If your house is too hot for plants, try reducing the thermostat temperature of your central heating. You will get used to the lower temperature in your house very quickly and your health may improve.  Your wealth certainly will as your electricity or gas bill drops. The ultimate solution?  Seal your growroom and invest in an air-conditioning unit and CO2 emitter.  We’ll be looking at AC units, evaporative coolers, ultrasonic humidifiers, and reservoir chillers in the next issue.

Heat from bulbs

H.I.D. lights produce a lot of heat.  And as bulbs become older they produce less light and more heat!  So there we have two very good reasons to change them regularly!  Air-cooled lights allow you to isolate the hot air around the bulb and vent it outside of your growroom! Water-cooled lights have been offered in the past, the dangers are so obvious that we don’t need to mention them. Protect your rootzone by covering pots or tanks with white or silver reflective corriboard or plastic sheet to reflect away the direct heat from the lamps. The roots are particularly sensitiveve to heat. Leave some space around the stem to allow it to breathe.

Insufficient air transfer

It’s no good just moving the air in your growroom around with an oscillating fan.  In the absence of an A/C unit, you are going to need to provide fresh air for you plants to breathe.  This also means you can replace hot air with cool, and so reduce the temperature in your growroom.

In order to create an effective inflow / extraction system you are going to need to know the volume of your growroom, and thus the amount of air you are trying to exchange.

Everest On Air Transfer

Check out our complete guide to growroom ventilation (based on energy rather than room volume.)

A simple rule of thumb is that you need 12 times the volume of your room in air moved every hour. If your actual room is much bigger than the area used for growing then imagine a comfortably-sized room around your plants and use that size in the calculations. For example:

height x length x width                   2.3m height x 4m length x 3m width = 27.6m³      For room measurements in feet divide the ft³ by 35.3 to get m³

12 x 27.6m³  = 331.2m³ so the fan you select should have more than 331 m³ per hour of airflow.

If using a carbon filter multiply the number by 1.5 as some of the power of the fan is used in forcing air through the filter. Ducting should be as straight as possible to avoid reducing the airflow.

CO2 reduces the need for air-changes due to the plants being more resistant to heat and not losing so much water. The plants should still not be allowed to get above 30 degrees celsius. If the heat is not too bad 8 changes of air per hour will be enough.

The air you draw out of your growroom should be taken directly from around the H.I.D. bulbs and / or from the top of your growroom (as warm air rises).

In attics, consider investing in some vented roof tiles fitted.  You can fit flexible ducting directly on to these and pump hot air directly out of your growroom to the outside world.  Also, note that many modern houses are now built with ducting from bathrooms and cookers that leads straight into the loft and out through the roof.  It’s possible to double up these precious routes to the outside world by fitting a ‘Y’ shaped adaptor that allows two ducts to share the same exit.  But remember, don’t interfere with chimneys or ducting from boilers, gas fires or any other sources of carbon monoxide – mistakes can be fatal!

It’s important to balance the rate of “air in” with “air out”.  When choosing your inflow fans and extractors, I think it’s best to ‘over-spec’ slightly and run them through a fan controller unit such as a Klimavator or Prima.  Too much air passing through your growroom will have a drying effect on your plants.  Whereas an imbalance of inflow and outflow can have strange effects too – I recall a pair of friends who spent most of their money on half a dozen standard 600 watt lights, blazing away in their attic.  The high temperatures and swampy feel in the growroom  indicated that they should have allocated more of their budget to more suitable inflow and extraction.  They tried to fix the situation by pumping air from the downstairs kitchen (the coolest in the house) up into their attic through a huge ‘elephant trunk’ of ducting attached to a monster RVK 350 fan.  They fired it up and the cool kitchen air dropped the temperature in their growroom by 10 degrees celsius in as many minutes.  But, because of the inadequate extraction, the hot swampy attic air was simply pushed all the way downstairs back into the kitchen!  This, of course, quickly rendered their efforts redundant.

Poor insulation

If your growroom is well insulated it will be less affected by changes in ambient temperature.  This is why cellar growers (insulated and cooled by moist mother earth!) enjoy such uniform temperatures (albeit often with higher humidity thrown in).

Heat from ballasts

Opt for lights with remote ballasts – more or less the norm these days.  Ballasts give off a surprising amount of heat.  It’s worth packing these boxes of joy away for a number of reasons – not least, safety!  You don’t want ballasts anywhere near your nutrient solution reservoir any more than you want water-cooled lights, for example!  Invest in ballasts that have longer cables so you can stash them away from all the action.

Thanks to UrbanGarden Magazine for the Article- Original Page Here

Happy ALOHA Friday everyone. Hope you had a productive week in the garden. Looking at the quickly building database of articles we have going here at the PGS Definitive Growers Blog, I realized that we don’t have any good information on CO2 enrichment. CO2 is a crucial part of plant growth, with or without extra CO2 added to your room. Air outside has larger amounts of CO2, and is one of the reasons why outdoor plants do so well. Just bringing in more fresh air from outside will increase CO2 levels naturally. CO2 enrichment with a generator or a tank can greatly increase yield, strength and vigor but needs to be addressed carefully….. Here is a great article from UrbanGardenMagazine on the topic…. Have a fantastic weekend!

Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. It is often referred to by its formula CO2.  Carbon dioxide is an end product in organisms that obtain energy from breaking down sugars, fats and amino acids with oxygen as part of their metabolism, in a process known as cellular respiration. This includes all plants, animals, many fungi and some bacteria. In plants using photosynthesis, carbon dioxide is absorbed from the atmosphere.

What is in the air?

99% of the air consists of nitrogen (78%) and oxygen (21%).  Only a small amount of the remaining 1% is made up of CO2.  In fact, the air only consists of 0.03% CO2.  In spite of this low concentration, CO2 is the basis of life.  Humans and animals are just part of the big cycle – in short, we eat plants, breathe out CO2, and the plants use that CO2 for photosynthesis!

The basis CO2 for sugar and amylum

The first step of photosynthesis is the joining together of two parts of carbon dioxide.  After this step the first organic molecule is created.  Three of these units are one sugar molecule.  There are six CO2 molecules, one sugar (C6H12O6).  Amylum is the name given to lots of sugars attached to each other (poly-sugars).  It is precisely by forming these sugar chains that plants manage to store energy from the sun.  All this occurs during the daytime, with light acting as the ‘motor’ and water as the ‘fuel’.

How does CO2 get into the plant in the first place?

Leaves have pores which can be actively opened and closed by the plant.  Water evaporates through these pores and a constant stream of water is maintained from the roots to the leaves.  Air comes in through these pores and spreads more or less unhindered in the plant.  CO2 is not dependent on special pores and is transported by leaf calls or with the perspiration water.  By using CO2 in the plant, an under-pressure of CO2 is found in the leaf pores and around the plant that can be immediately compensated by the endless amount of air.  That is why the photosynthesis is on full speed, in spite of the small concentration of CO2.

The penetration of CO2 into the plant depends on the leaf pores.  During the night the pores are closed.  If the sun rises or, as in the case of indoor growers – the lights are turned on, the plant opens it pores, the water begins to flow and phososynthesis starts.  Sometimes a plant closes its pores in the daytime.  If the sun gives so much power that the products of photosynthesis (sugars and amylum) are produced in too large quantities they can not be transported away and a surplus develops.  This is a sign for the plant to close the pores to stop the supply of CO2.  When the traffic-jam is over, the leaves open their pores again and a healthy photosynthesis commences once again.  Another reason for the plant to close its pores during the daytime (and prevent the penetration of CO2) is a massive lack of water and too high temperatures.

If you are growing indoors in a closed room CO2 deficiencies are possible (this could never occur outside because of the endless supplies of CO2 at a guaranteed concentration of 0.03%!)  Deficiencies can happen if the intake of the air is not well calculated and there is not regular air refreshment.  Take care that the intake and the outlet of the air is optimal – too much is better than too little – so the concentration of CO2 is always at least at normal air-level.

In the smaller grow room, the CO2 quantity can also fall as a result of inadequate ventilation.  Sufficient ventilation and mixing of the air in the room is crucial for healthy plants.  If you grow resin-producing plants then take note that resin increases leaves’ resistance to light – this is supposed to be a reason why plants produce more resin when exposed to more light.  The light that falls on the surface is reflected by a protective layer of resin.  And not only the intake of light – but also the intake of air is prevented by hairs.  So, if your plants are hairy and resinous, you really must invest in strong ventilation!  Not only are you refreshing the air around your plants, but you are also ventilating away any high temperatures.  You might well be surprised at the amount of air movement your plants will enjoy – and it also promotes a thick stable stem!  Plants that are grown in poorly ventilated or windless rooms are often found lying on the floor during the later blooming period due to weak stems.

Most of us simply rely on extraction and fresh air inflow to introduce more CO2.

The average level of CO2 in the atmosphere is about 350 PPM [parts per million]. However, the optimum level is in the 1000-1500 PPM range. Growers who inject extra CO2 into their grow-rooms to achieve these levels have reported a 25-40% increase in yield!

Thanks to Urban Garden Magazine for the Article Photos inserted by Pete, Original Page Here

Organic nutrient manufacturers are very secretive about their recipes. This makes it very difficult to write about them except where I have seen the results. Some commercial organic nutrients have been certified by independent organic bodies. There are some products that are claimed to be organic but have not been certified. This may be simply because the manufacturer wants to keep the ingredients secret. In the cases where the nutrient is not certified you have to decide whether you trust the manufacturer. There have been cases where the producer just uses the word organic to mean that there is some part of the nutrient made from organic products with a base of chemicals.

It is a common myth that you cannot provide enough nitrogen with organic nutrients. With modern organic nutrients it is quite possible to over-fertilise with nitrogen, so always use the nutrients as recommended on the labels. Don’t assume stronger solutions are better. Too much, even of organic nitrogen, will result in weak growth that is more vulnerable to pest attack. This can provoke the production of too many leaves, few flowers and tasteless harvests.

Bio Sevia is one of the latest organic nutrients and will give excellent results surprising to those who may have tried older attempts at organic nutrients made by less technically-minded producers. I know some people who have managed to use the new Bio Sevia range in hydroponics but the technique is so intricate that it would require an article on its own. I would recommend only using organics in soil unless you want to learn degree-level hydroponics. The use of their Trichoderma fungus additive is very much recommended to drive the best results from your plant. Bio Sevia is certified organic by Qualité France.

Canna have recently revised and improved the formulae of their Bio Vega or Bio Flores. They should now give even better results than before. Simple to use they are another one part organic nutrient for use with soil. The ingredients are all plant extracts but only hops are specified on the labels. Hop waste is a very rich organic nutrient mostly obtained from the beer brewing industry. For the those who don’t know the hop, the hop vine is a massive, fast-growing plant that reaches 8 metres tall from ground level every year. The hop vine drags huge amounts of minerals through its large root system. One of the problems of growing hops is feeding them fast enough to keep up with their growth. The hop flowers contain lots of nitrogen, potassium and phosphorus as well as most of the minor minerals that were present in the soil in which it was grown. Canna Bio Flores and Vega are certified organic by the official organic certification body for the Netherlands.

Another Dutch certified organic nutrient with as many satisfied growers as Canna is Bio Bizz. Although they do not reveal the ingredients they are all plant- and mineral-derived. As they a little cheaper than the Canna products they are used by the majority of organic growers whom I know. Perhaps that says more about my friends than the relative quality of the two nutrients.

An old favourite that is still used by many organically-minded gardeners is Earth Juice. The manufacturers give the ingredients on the label. So, if you want to add your own favourite additives you will know whether they are already in the mix. Because of the high content of bird and bat guano it can smell quite objectionably bad to some people. Earth Juice contains molasses so you will not need to add any carbohydrate additives like Carbo Load. Both the bloom and grow formulae contain phosphates and potash so you may not need to add them to your soil.

Most one part organic nutrients will be short of phosphorus and/or calcium as they are one part nutrients (not A & B). It is quite difficult to make calcium and phosphate soluble at the concentrations needed in a one part nutrient. This is quite easy to allow for by adding rock phosphate or bonemeal to your soil mixture. The fungi in your soil will make these available to the plant.

Local Harvest is another great organic liquid Organic nutrient that performs just like a salt/chemical based fertilizer would. Based out of Sebastopol Ca. They have a Grow and Bloom and a Calcium supplement. I have heard great things about this product.

Another way to feed your plants organically is to make your own “compost tea”. Though some of these are made from well-rotted garden compost dissolved in water there are simpler, faster methods. Garden manure will contain a large range of organisms, not just those that help your plants. It is not possible to reproduce the entire ecosystem indoors so you must select those that help. These live teas can be made from fresh plants and manures. Traditional recipes involved comfrey, nettles and other herbs rotted in water for two weeks. This produced a very stinky liquid that was very good for the plants.

Modern compost teas are made with fungal or bacterial starters Some contain both bacteria and fungi. An air pump is essential to ensure that the mixture stays oxygenated. Keeping high levels of oxygen in the tea reduces the smell to tolerable levels but it is still best to put your composting bucket in a relatively unused room. High oxygenation also benefits the better types of bacteria and fungi. Compost tea made without oxygenation could produce very high levels of the most dangerous fungi and bacteria, for you and your plants. Using Liquid Oxygen or other hydrogen peroxide solutions is not possible with compost teas as the useful organisms will die immediately they are added.

Bacteria-dominated teas should contain plenty of protein rich plant matter such as vegetable waste, especially from beans and leafy vegetables. The bacteria-dominated teas can be diluted and used as foliar sprays when plants are young.

Fungi-dominated compost teas should be given small amounts of molasses or other sugary foods to feed the fungi. Too much sugar can be detrimental producing an overgrowth of common yeast, it is best to add a little every day. Phosphates can be added by the action of the fungi or bacteria on rock phosphate or bat guano.

Compost teas must always be made with chlorine-free water. Chlorine is added to the water-supply because it kills a wide range of bacteria, fungi and other disease-causing organisms, having the same action as bleach. It will also kill your beneficial organisms. You can get rid of low levels of chlorine by leaving the water to stand overnight but to be absolutely sure use a charcoal-based water filter or Reverse Osmosis filter.

If you don’t like the idea of all this bother for your plant food, you can get the same benefits by using any of the liquid organic nutrients as a short cut. Make up the solutions in your reservoir as directed on the bottles. Add a bacterial or fungal starter. Keep the mixture heavily oxygenated by an air pump driving air through airstones. Clean the airstones regularly so they do not become blocked. Use the liquid to feed your plants whenever they need it. After a week make another batch of nutrient. If your mixture smells sweet and yummy you can keep a little of your old nutrient tea in the bottom of the reservoir to start the new batch. However, after some time you will lose some of the organisms you need and should add the starters occasionally. You do not have to wash your reservoir thoroughly, the beneficial organisms should be keeping the nasty ones in check

Thanks Urban Garden Magazine for the Article – Original Page Here

You don’t need chemicals to supercharge your garden.  Mother Nature has more than her fair share of tricks up her sleeve at your disposal!

For this post I am going to mention just a few of the many powders that are approved to use in organic cultivation. I am not going to give recipes and quantities to use because there so many different types of soil mixes available, many already having some of these additives already included. I also won’t refer to specific brands – again because there are so many!  All of these supplements are easily available from PGS where you can ask for further advice regarding your soil mixture. Many people are surprised that these rocks from mining can be used in organic gardening but they are essential in indoor soil mixes as there is no subsoil under the plant to provide these minerals.

Bat Guano is a euphemism for bat shit. This is usually mined from bat caves in tropical and sub-tropical countries. Bird guano has been used but bat guano has a legendary reputation among indoor growers. The results on heavy-feeding plants such as fast-growing vegetables can be amazing. It is quite smelly, though there are aged versions that do not smell so offensive. Of course, the contents vary according to the diet of the bats that dropped it. Bats have a very nutrient-rich diet. As they must be as light as possible to fly they do not keep food in their guts for very long. This means that the manure they produce is still full of nutrients, many forming complex chemicals similar to very rich organic soil. Some cave-dwelling salamanders that are normally meat-eaters live happily on a diet of bat guano. Most bats eat insects and insect shells contain large amounts of chitin, the same as the cell walls of fungi. Chitin is like a starch with added nitrogen. For this reason the bacteria and fungi in your soil can use it efficiently, it is a food they recognise. As well as nitrogen it contains high levels of phosphorus and potassium and many micronutrients. All this adds up to a very powerful fertiliser and you must be careful not to overfeed your plants, especially when the soil has already got fertiliser in it. You can do more damage to a plant by adding too much rather than too little nutrition, burning the delicate feeding hairs on the roots.

Quantity: Suggestions range up to a maximum of 4 to 5% of the total soil though this is only recommended for very heavy-feeding plants.

Clay powder is, like diatomite, a method of adding natural silica minerals to your soil mix. Not to be confused with clay pebbles which have been baked into a ceramic which hardly interacts chemically with the soil. These are much more complex minerals, with lots of essential micronutrients. Do not dig up some clay from your local riverbank, it may contain high levels of toxic heavy metals, even if it appears to be from an unpolluted area. I am afraid to say it is sensible to buy the relatively cheap branded powders from your local hydroponics shop. Their ability to absorb toxic chemicals and resist changes in pH can help a soil mix stay “sweet” and healthy for longer. The silicates in some clays are easily transferred to the plant. The advantages of this are harder, happier, pest-resistant plants that produce higher yields. The silica is used by many plants to strengthen their cell walls. Like microscopic shards of glass these “phytoliths” (from the Greek for plant stones) blunt insect teeth and preventing parasitic fungal entry into the plant. They do not harm human health when using the plant.

Quantity: The only reason for not having a soil made entirely of clay is the resulting lack of airspaces. The dense structure of the soil mix makes it hard for the roots to breathe and penetrate new volumes of soil as they grow. Generally only a little clay powder is used as a supplement.

Diatomite is a soft, crumbly rock that is pH neutral and will not affect the pH of the soil. It has many industrial uses including stabilising dynamite. Often used as a hydroponic substrate due to its chemical stability, though more expensive than clay pebbles. It is formed from the fossilised remains of silica-shelled microscopic algae. The carapaces of these diatoms are sometimes spectacular in their beautiful intricacy. The tiny spikes on these circular are deadly to many insects. They cut open the hard, water resistant shell of the insect which then dies of dehydration. It is also used against slugs and snails in the garden but must form a physical barrier around the plant. As long as you do not inhale the dust it will not harm humans. Some of the important mineral silica can be absorbed by the roots. By adding diatomite throughout your soil you can also provide a different habitat/refuge for fungi and bacteria that helps the biodiversity in your soil.

Quantity: Up to 100% of your medium can be made from diatomite as, like the clay powder, it affects the pH and saltiness of soil water very little.

Dolomite is a type of rock named for its discoverer, Déodat de Dolomieu. He found the rock in a mountain range that is a part of the eastern Italian Alps now known as the Dolomites. Diatomite is easy to confuse with dolomite as it is also a white rock. The mineral is sometimes called dolostone, dolomitic limestone and magnesian limestone. This last name tells us the difference from normal limestone, it contains magnesium as well as calcium. The mineral comes out of saturated solutions in salty lakes or the sea, so is also quite solidly crystalline compared to ordinary limestone. The big difference that this makes is the higher resistance to attack by acids. Ordinary limestone will, if added in excessive quantities quickly make the soil alkaline, with a pH higher than 7. Most plants will be very unhappy at this. Dolomite only changes the pH slowly and in response to very acidic conditions. As it adds both magnesium and calcium when it dissolves it is the ideal pH adjuster for soil in indoor gardens. The actual quantity you add does not matter too much as excess will do little except sit there.

Quantity: Add this around the sentence as is – Quantity: The actual quantity you add does not matter too much as excess will do little except sit there. A heaped tablespoonful for every four litres should be sufficient to “sweeten” a “sour” (acidic and usually nasty-smelling) compost mix.

Rock phosphate is another calcium-based mineral, though there should be lower amounts of other minerals as well, depending on the source from which it was mined. It will not change the pH at all and will hardly dissolve. “What good is that?” you ask. If you maintain a friendly fungal colony in your soil those fungi will form bundles of threads of hypha around each grain of rock phosphate and passing the nutrients along to the roots of their symbiotic ally, your plant. Phosphates are one of the most difficult nutrients to get into the plant as most metals found in nutrients form insoluble phosphates. By adding the phosphate as a solid you can get higher levels of minerals such as calcium, iron and zinc in your liquid nutrient. Again, excess should not matter as the fungi will only mine what they need. Remember to keep your fungi as happy as possible for the fastest growth responses from your plants.

Quantity: About 5% rock phosphate is ideal, though more may be necessary if the rock phosphate powder is very lumpy or solid rather than a fine powder or crumbly mass.

Thanks to Urban Garden Magazine for the article, Photos added by Pete – Original Page Here

One last note from us here at PGS, when ever you amend your grow medium with any supplements, always keep it simple and go light on the dose…1-866-PGS-GROW

Wow, this week is going by super fast! We have recently developed a relationship with the ultra hip “URBAN GARDEN” magazine. We have enjoyed every issue that has come out, and find all the information to be accurate and helpful. Upon going to their website today we found even more great articles and information that we know everyone is going to really enjoy…. Here is their mission statement, I like it!

Growing is our PASSION!

It’s no secret that everyone involved with Urban Garden Magazine is completely crazy.  Crazy about horticulture that is.  Whatever you want to grow, however you want to do it, you’ll find Urban Garden Magazine tells you what you want to know.

Our Core Aims and Values

• To broaden and diversify the appeal of greenhouse and controlled environment indoor gardening.
• To challenge preconceptions about the scope and applications of water culture and soiless gardening techniques.
• To be a reliable source of practical information on all different forms of domestic horticulture.
• To act as a bridge between manufacturers, wholesalers, retailers and customers for effective two-way commercial communication.
• To educate on environmental issues and actively promote sustainable living and associated techniques and technologies.
• To promote awareness on food consumer issues.
• To demonstrate that growing is not only a fun pastime, but also an important life skill.
• To get the world growing again – young, old, rich, poor and everyone in between needs to reconnect with Mother Nature!

So how’s that for starters?  And aren’t we bang on the money?  With rising fuel, energy and food costs doesn’t it make sense to start producing your own food at home, or at your local allotment?  We want to inspire everyone, no matter what their domestic situation, to get growing.  Even somebody living in an apartment on the 37th floor can produce surprising quantities of their own vegetables and herbs.

We really have fun with their tongue and cheek articles and just can’t get enough of the information they share… KUDOS URBAN GARDEN!!

Want to see more?

Take a look at these great taster articles:

• Homegrown Superfoods
• The Right to Drive vs. The Right to Survive:  How Biofuels Could Kill Us
• How to Grow Mushrooms Indoors
• Solid Organic Soil Supplements
• Biological Pest Control