An Element Too Good To Pass Up: The Benefits of Silicon to Your Garden

Si on Periodic table

Si on Periodic table

Would you use a product that would increase your harvest weight by as much as eighty percent? What if it also provided increased tolerance to environmental stressors such as drought and high temperatures, provided resistance to insect attacks, and additionally had been proven to protect your crop from powdery mildew (Sphaerotheca fulginea), root rot (Fusarium oxysporum), damping off (Pythium), and grey mold (botrytis cinerea)? Now, what if I told you this product is real, that it is available, and that the above list of accolades does not even scratch the surface of what it has been proven to do?

This miracle product happens to be the second most abundant element on the surface of the earth: silicon. Although not regarded as one of the 16 essential nutrients that plants must have to grow, silicon may prove to be the best addition to your fertilizer regimen you can make. Plants have certainly been shown to grow in hydroponic solution devoid of silicon, but when the same plants are grown with silicon, tissue analysis has shown that silicon accounts for as much as 10% of the dry weight of the plant. Everyone wants bigger harvests, and using silicon could be the key. A study conducted by the University of Florida found that silicon responsive plants had “dry weight increases (which)…ranged from 6-80% depending on the species” (Chen et al, 2000).

So how does this “non-essential” element have such a huge impact on so many facets of your plants’ existence? Silicon performs its multitude of functions in two ways: by the polymerization of silicic acid leading to the formation of solid amorphous, hydrated silica, and by being instrumental in the formation of organic defense compounds (Epstein, 2009). To simplify, silicon is actively transported into the plant similarly to macro nutrients like potassium. From there it moves up the xylem and is distributed out to the growing shoots. There, the silicon forms larger polymer chains (polymerization) which allows plants to deposit silicon in the form of solid amorphous (non crystalline), hydrated silica which is then incorporated into the plant’s cell walls, thereby armoring the plant’s cells against rasping and sucking insects. If you are growing leafy greens think how much better the texture of the leaves will be when every one of the millions of plant cells has thicker cell walls from the added silicon.

Additionally, silicon is deposited in the trichomes of plants, according to Epstein; it “is the silica in trichomes that lends leaves and awns (stiff bristle or hair-like appendages in plants) the roughness and the toughness that impede the penetration of herbivores and pathogens through the cell walls. It acts as a physical barrier.”

The other mode by which silicon benefits your plants is in its ability to promote the synthesis of organic defense compounds. When a plant is under attack by insects or pathogens it sends out chemical messages which trigger the plant’s natural defenses. A study conducted on cucumbers yielded conclusive proof the plants were protected from fungal pathogens by the presence of silicon in the hydroponic solution (Cherif et al, 1992).

Another benefit of the use of silicon is that it balances the nutrient absorption of your plants. Silicon can balance nutrient elements in plant tissue through the suppression of Al, Mn, and Na, and by mediating the uptake of other elements like P, Mg, K, Fe, Cu, and Zn (Chen et al, 2000). When used with peat or bark based soil/soilless mixes, silicon prevents the over-acidification of the mix, which can lead to pH induced nutrient lockout, as well as inhibiting the absorption of toxic elements like aluminum. When anthuriums were grown in soil with available aluminum the tissue tested had 150 PPM of aluminum, while the plants grown in the same soil but fed silicon tested at only 41 PPM.

One bit of advice when introducing silicon additives into your feeding program: silicon products must be the first thing added to a fresh reservoir of water, even before base nutrients. By their inherent chemical properties silicon additives are alkali, and because most fertilizers are acidic they must be diluted before they are added to a hydroponic reservoir or any water fertilizer mixture. This will allow for the concentrated alkali silicon solution to diffuse, thus preventing localized chemical reactions from causing the formation of undesirable nutrient precipitates.

Silicon can be a cure, a booster, a medicine, and a messenger. It can counteract damage to your plants from extreme temperatures or prevent the absorption of toxins that would otherwise destroy your plants. It can send insects to more inviting hosts, and it can increase the weight of your harvest. Silicon truly is a multipurpose beneficial element that should be in every gardener’s toolbox. Think of it as the best and cheapest plant insurance you can buy!