Additives

There’s no doubt that UK growers love their additives and with good reason, used correctly a decent additive can seriously boost the growth rate and yield of your crop; forcing your lovely plants to perform just how you want. Whether it’s better root development, faster growth, less vertical stretch, more flowering sites or bigger, denser buds there’s an additive for every occasion. The nutrient manufacturers have certainly clocked that there’s no hesitation amongst growers over here to ‘chuck another bottle in’; visit any good grow shop and you’ll see a huge array of colourfully branded bottles, bags and boxes, all jostling for your attention.

There’s no doubt that UK growers love their additives and with good reason, used correctly a decent additive can seriously boost the growth rate and yield of your crop; forcing your lovely plants to perform just how you want. Whether it’s better root development, faster growth, less vertical stretch, more flowering sites or bigger, denser buds there’s an additive for every occasion. The nutrient manufacturers have certainly clocked that there’s no hesitation amongst growers over here to ‘chuck another bottle in’; visit any good grow shop and you’ll see a huge array of colourfully branded bottles, bags and boxes, all jostling for your attention.

But, are they worth having? Well, in a word, yes. They do work, albeit to varying degrees, if they didn’t work, nobody would buy them again! However, it’s worth noting that before venturing into the wonderful world of additives you need to have your environment right. There are no magic potions available (despite claims from some manufacturers) that will sort your plants out if the environment is poor. Granted, certain compounds will help your plants during times of temperature stress or pest attack, but if your plants aren’t working at their optimum they aren’t going to uptake the majority of that expensive bloom stimulator that you’re chucking in the tank. You’ll just be pouring money away.

Got it? Good.

Root and bloom stimulators are now pretty much common place in any grower’s nutrient regime, so we won’t cover topics that most of you probably know. Instead, let’s take a look at some of the additives that you may not have paid attention to, but can make a huge difference when used effectively.

Mycorrhiza

This is a beneficial fungi which is mixed into the growing media and also sprinkled around the roots when potting up. The mycorrhiza obtains nutrition by invading the root zone of the plant. In doing so, these fungi assist the roots in the uptake of minerals from the growing medium and it’s this added nutrient uptake that leads to faster plant development and rapid growth.

When added to soil or coco, the mycorrhiza quickly establishes itself and forms a symbiotic relationship with the roots; breaking down elements and making them available to the plant, whilst feeding on the carbohydrates that the plant produces. Think of them as a root extension, increasing nutrient uptake and speed of development, whilst simultaneously eating the waste that the plant puts out into the medium.

It works because the fungi form a fine network of thread-like strands - called hyphae for all you nerds out there - that serve as an extension of the plant’s root system. There may be up to 10 feet of hyphae growing out from each half-inch of root that is infected by mycorrhiza. The diameter of the fungal hyphae can be just one-fifth of even the smallest root hair and will be many times longer, allowing it to explore areas of the growing media that the roots of the plant would not be able to reach on their own. By reaching the previously ‘untapped’ nutrients in the growing media, the plant receives better overall nutrition and is more likely to reach its optimum potential i.e. bigger yields.

Mycorrhiza fungi are especially beneficial in helping the plant access nutrients that are not particularly mobile in the growing medium, such as phosphorus and potassium – key elements required for packing on the buds! What more could you ask for?

Products containing mycorrhiza fungi can be purchased from any grow shop – there are loads of brands about now – and, as mentioned above, all are applied when potting up in order to artificially introduce the fungi into your soil or coco. Another point of interest to the home grower is that the fungi will not only increase plant growth and vigour, but will also make them more tolerant to stresses, such as temperature fluctuation, over or under-watering and attack from root pathogens. And, as every good gardener knows, the less stressed your plants are, the less stressed you are!

Trichoderma

In natural soil, trichoderma are usually the most prevalent type of fungi. So the majority of compost growing media available from your local grow shop will have trichoderma present, however you can still add more and with good reason... 

Trichoderma is an aggressive fungi which will readily colonise on the roots of your plants, the most competent strains can be added to growing media, or even to seeds, and are able to grow along roots as they develop. This is why many growers choose to dip their fresh cuttings in trichoderma powder, as the fungi will remain present on the roots of the plant throughout its cycle (although it is a good idea to reapply every 30 days to keep numbers effective).

The strains of trichoderma available at your local grow shop are known to control every pathogenic fungus for which control has been sought. They work on two levels;

Trichoderma actively takes over a root zone and makes it difficult for more damaging pathogens, like pythium and rhizoctonia, to compete for space on the roots and for nutrients. Once established on the roots of a plant, trichoderma will detect other fungal organisms within the vicinity and grow towards them. The trichoderma then coils itself around the organism and breaks down the cell walls by releasing enzymes, paralyzing the offending organism and rendering it inactive. Bad boy!

Once they come into contact with roots, trichoderma will colonise the root surface and physically penetrate into the root itself; which in turn induces the plant to "turn on" their natural defence mechanisms making them stronger and less susceptible to attack. Think of when you have your vaccinations before going abroad, when your body is attacked it produces ‘anti bodies’
to fight the attacker, same thing here. By fighting against the attacking
trichoderma, the plant bolsters its defences marking it harder for any other pathogen to penetrate. Clever stuff.

So to recap, it’s mycorrhiza for faster development and increased growth rates and trichoderma for pathogen control and defence. But, I hear you thinking, if trichoderma is so aggressive, won’t it attack any mycorrhiza that has been added to the root zone?

Well, a good many scientific studies have been carried out to monitor the effects of adding both fungi to the root zone and the general consensus seems to be that because both perform separate jobs they work in synergy, rather than cancelling each other out.

Ultimately, the key to remember is that the level of beneficial fungi activity in the root zone will reach a saturation point depending on the amount of food available for them to eat. So, keep conditions right, reapply your beneficial fungi at least once every 30 days, keep the root zone well fed and let Mother Nature do her work.

Silicon

This is a massively significant additive, which will be particularly important for those of you growing in hydro or coco. In nature, soil water – the run off from naturally occurring soils – can contain around 400 ppm of Silicic acid, which is readily absorbed by plants. Studies of tissues taken from plants grown in naturally occurring soil show a silicon content of up to 10% of dry weight. In some cases, silicon can be found in the same quantities as calcium, magnesium and phosphorus. Certain grasses can even contain silicon at a higher percentage than any other mineral.  With silicon being found in such abundance in plant tissues, there is now an argument that it should be considered as a relevant macronutrient.

Now, you won’t find silicon included in your base nutrient as it’s difficult to mix with other elements and maintain stability. It needs to be given as an additive. But what does it actually do?

Well, silicon effectively ‘builds’ the plant, acting as the cement between the bricks in the cell walls and between the actual cells themselves. It increases the structural integrity of the plant, making stems and branches thicker and stronger, and leaves greener and tougher.

This means that when you give your plant silicon you improve the cell development and integrity, increasing their overall physical strength. You’ll notice that your plants are sturdier and the leaves are tougher. This has wide reaching benefits; they’ll be better protected against attack from pests and disease, more resilient to changes in environment and, obviously, you’ll see an overall increase in their weight and bulk.

Like most feeds and supplements, silicon can be administered to your plants in two ways;

• Mixed with your regular nutrient feed and administered to the roots. This is relevant to the soluble silicate additives.
• Sprayed onto your plant as a foliar feed and absorbed through the leaves.

Remember, silicon is the cement that that sits between the bricks in the cell walls of your plants and once it has been deposited it will not move around inside the plant. This means it’s important to continuously feed silicon throughout the entire life cycle. This will ensure that all new growth in your plants benefits from the effects.

Flushing additives

Not every additive is designed to increase yield. Quality is as important as quantity. Any plant that has been raised on mineral feeds and additives should be flushed, regardless of the growing method or growing medium used. In hydroponic growing methods plants usually have constant access to mineral nutrients and, provided the solution in the reservoir is balanced, will constantly take all the elements they need via active uptake. These elements will be stored, in the root zone and plant sap, all the way until harvest.

End product from plants that have not been flushed can suffer from a ‘chemical’ taste, smokers often complain that hydroponically grown weed has a different taste from soil grown, whereas in reality it is more likely that it just hasn’t been flushed properly.

Flushing also affects the ‘burn’ of the end product. Next time you’re smoking on some dealer-bought weed, take a look at the ash on the end of the joint; if it’s been properly flushed, the ash should be light grey, with a fine, powdery texture. Ash created from burning weed that hasn’t been flushed will be black, with a much more solid consistency and – in particularly bad cases – can pop and spark as the impurities still contained are ignited. 

There are various flushing agents on the market, each based on different techniques of removing, or forcing the use of, excess nutrients stored within the plant. These techniques include;

Stress – when the flush is administered it creates a root stress that forces energy in the plant to be expended, therefore using up the excess nutrients stored and ripening the plant at the same time. Some of the flushes that employ this technique are so powerful that they actually destroy the roots of the plant, triggering a survival instinct, forcing all of the energy into reproduction (i.e. the buds).

Mineral salts – a good technique for pure hydroponic systems where the roots are exposed. Large mineral particles are added to the flushing solution, these particles are too large to be taken up by the plant, but when washed through the roots will attract any excess mineral deposits that have built up and wash them away.

Hormones – flushes containing natural plant hormones will trigger a natural reaction in the plant that forces it to mature and finish. This uses up excess minerals stored and also ripens the fruit, improving quality and yield.

Some of the better flushes on the market use a combination of techniques to get the best result. However, if you’re down to your last few pennies and decide to scrimp on a flushing agent, try giving your plant water with a pH of 5 for three or four days. The acidic water will stress the plant and force it to use up any excess of salts.

Happy growing!