Silica is one of those things you’ve likely heard of a million times, but you might not actually know what it is, much less what it does. So, what is silica exactly?
According to the dictionary, silica is “a hard, unreactive, colorless compound that occurs as the mineral quartz and as a principal constituent of sandstone and other rocks.” Glass is made of silica, sand is often made of silica (depending on the rocks that ground down to comprise it), and of course, it’s also found in soil. In fact, the mass of the Earth’s crust is 59 percent silica and is the main component in 95 percent of identified rocks. Silicon is simply deoxidized silica.
When we think of sand in the soil, aside from helping with drainage, we often think of it as benign. When it comes to silica sand, however, it’s anything but. There are many data-supported benefits to adding silica to your cannabis crop feeding regimen. Silicon helps plants fight disease and pests, build strong cell walls, absorb nutrients, fight metal toxicity, and ultimately, improve crop yield.
Silica Helps Reduce Powdery Mildew In Cannabis Crops
The root and foliar application of silicon has proven to help reduce powdery mildew in a wide variety of crops. One such widely studied crop, and its relationship with silica and powdery mildew, is wheat.
The study, “Effect of root and foliar applications of soluble silicon on powdery mildew control and growth of wheat plants,” published in the European Journal of Plant Pathology in 2007, examines how silicon (Si) impacts powdery mildew on this staple crop. The study reads:
In terms of powdery mildew control, root applications at 1.7 mM Si gave consistently the best results, reducing disease severity by as much as 80%, regardless of the product used.
Cannabis cultivators report that the use of silica in soil has the same effect on cannabis plants. Every cannabis grower knows that powdery mildew is an enemy to cannabis plants. Adding silicon to your feeding program is an affordable and easy way to help prevent this menace from reducing your yield, or even ruining your crop altogether.
Silica Defends Against Pests In Your Grow Op
Botany experts have long theorized, and proven with studies, that silica in soil helps deter herbivores from eating plants. Previous studies have shown that silica in grass leaves defends them against small herbivores, which avoid high-silica grasses and digest them less efficiently. This study tested the idea that silica can reduce digestibility by preventing the mechanical breakdown of chlorenchyma cells.
This theory was based on prior research. The study’s conclusion confirmed its theory, stating:
By reducing mechanical breakdown of the leaf, and that mechanical protection of resources in chlorenchyma cells is a novel and potentially important mechanism by which silica protects grasses.
Another study, titled, “Silica in grasses as a defence against insect herbivores: contrasting effects on folivores and a phloem feeder,” and published by the Journal of Animal Ecology, 2006, examined the palatability of grasses grown with varying levels of silica in the soil to the three herbivores field voles, locusts and armyworms. When given the choice between high- and low-silica grasses, all herbivores preferred eating low-silica grasses. Herbivores who weren’t given the option of low-silica grass, and had to eat high-silica grasses, grew at a slower rate than when fed low-silica grass.
While grass isn’t cannabis, and voles, locusts and armyworms aren’t common pests for indoor cannabis growers, these studies would certainly still be of interest to cannabis growers. After all, spider mites are folivores, and root aphids are phloem feeders, so it can be surmised that adding a little silica to your soil may help deter these crop-killing pests.
Silica in cannabis
Silica Helps Cannabis Build Strong Cell Walls
It’s long been theorized, and studies have indicated, that adding silica to the soil of plants helps plants build strong cell walls. According to another study published in the Annals of Botany in 2007, titled, “Silica in Plants: Biological, Biochemical and Chemical Studies”:
The incorporation of silica within the plant cell wall has been well documented by botanists and materials scientists.; however, the means by which plants are able to transport silicon and control its polymerization, together with the roles of silica in situ, are not fully understood.
Building strong cells is useful for cannabis growers because it makes their plants stronger. Sturdy cell walls mean sturdy plants, with thicker leaves, branches and stems. Strong plants are resistant to pests and breakage, plus they look healthier and just plain prettier. And who doesn’t want health, pretty plants, right?
Silica Helps Plants Absorb Nutrients
In addition to helping prevent disease and deter pests, silica may also help plants grow. Silica does this in a number of ways, one of which is that it plays an instrumental role in plants better absorbing nutrients. The biological processes in which silica works to help plants with nutrient uptake are complex and varied.
Many studies have shown that adding silicon to the soil of a number of crops will help said crops better absorb the chemical elements magnesium, nitrogen and potassium, even in grow conditions that are not ideal. As any cannabis grower worth their sodium knows, nutrient uptake is a crucial component to successful cannabis growing, and can greatly impact the quality and quantity of your cannabis. So, adding a product like Rhino Skin to your feeding regimen is a must for hydro growers whose plants will not benefit from silica that naturally occurs in soil.
Silica Helps Fight Heavy Metal Toxicity
Ecotoxicology and Environmental Safety, Volume 119, published the study “Mechanisms of silicon-mediated alleviation of heavy metal toxicity in plants: A review,” in 2015. The study aimed to help determine the role silica plays in helping alleviate the presence of heavy metals in plants. The study’s highlights state:
Si has been considered to alleviate heavy metal toxicity in plants and soils.
Si reduced the bioavailability of heavy metals in soil and uptake in plants.
Toxic heavy metals in plants can stress them out, causing a reduction in yield and overall plant health, in addition to the more obvious and troubling effect of being toxic to the humans who consume them.
Finding ways to fight heavy metal toxicity in soil is essential for growing healthy plants, especially for outdoor growers who have less control over their soil.
Silica Improves Cannabis Crop Yields
If you ask any cannabis cultivator what is the single most important issue when it comes to growing cannabis, they’ll likely answer “yield.” The more product you grow, the more money you can make. Finding ways to improve yield is a must for cannabis growers. Adding silicon to your soil or hydro solution is one way to help do that.
Studies in Plant Science’s “Chapter 7 Effect of silicon on plant growth and crop yield” states:
Integrated management of six macronutrients: nitrogen , phosphorus (P), potassium (K), sulfur (S), calcium (Ca), and magnesium (Mg) as well as the seven micronutrients iron (Fe), manganese (Mn), zinc (Zn), boron (, copper (Cu), molybdenum (Mo), and chloride (Cl) are the ones that most agronomists only consider as essential for sustainable crop yields. However, under special crop/soil agriculture conditions there are some “non-essential” elements, like silicon (Si) that will enhance crop yield by promoting several desirable plant physiological processes.
The “desirable plant physiological processes” include things like building strong cell walls and improving nutrient uptake. The many health benefits Si adds to plants all add up to a better yield. And more cannabis is something all gardeners can get behind.
How To Get The Most Out Of Silica In Your Grow Op
It’s been well-established that making sure your cannabis plants get silica is important for their health and for your bottom line. Once you’ve picked out the right silica product for your grow, using it correctly is the next step.
Silicon requires a pH higher than seven in order to stay soluble. Because of this, it can’t be included with other nutrients, rather, it has to be stored and added separately. It shouldn’t be added into a feed until all the other nutrients have been dissolved. If you’re using a two-part feed, silica should be your third part.
It’s best practice to dilute your silica with about one gallon of water. This will help avoid nutrient lockout that can occur when silica mixes with other nutrients.
Be sure to begin adding silica to your plants in the early veg stage. It’s also wise to stop feeding your plants two to three weeks into bloom, depending on the silicon product you choose.
Most silicon comes in the form of potassium silicate, and any product you choose will come with detailed instructions. Be sure to follow these instructions carefully, as silica behaves differently than other nutrients and should be treated as such. The benefits of this natural and simple element for plants are clear, but they’ll be of no use if you don’t use it properly.