Top Superfoods You Should Be Feeding Your Plants

This article originally appeared in Garden Culture Magazine UK33 and US31.

 

I know what you’re thinking; superfood for plants? Should I be mixing goji berries into my substrate?

The term ‘superfood’ has been around for quite some time. In the last decade, marketing agencies began using it to promote certain foods as particularly beneficial for health and well-being. Superfood by no means describes foods with an unusually high content of macronutrients, such as proteins, fats, and carbohydrates, because that would make low-fat curd cheese, palm oil, and sugar superfoods par excellence. Instead, the term refers to foods that contain many substances that otherwise occur only in small amounts, and which are said to have a health-promoting effect, such as omega-3 fatty acids.

How can this concept be transferred to your garden?

Like the above definition, I refer to such substances as a superfood for plants, whose effect goes beyond the provision of nutrients and has a positive impact on their vitality. They are, therefore, substances that are not necessarily rich in macronutrients, such as nitrogen, phosphorus, and potassium, and yet have a significant influence on plant growth.

Similar approaches are largely ignored in conventional agriculture, where nutrient salts are poured over the root ball of the plant to increase yields. For example, stinging nettle manure is denied any effect because it contains hardly any nutrients. However, it is rich in silicates, enzymes, and bacteria, and thus, promotes an active soil life, a robust plant, and improved nutrient uptake.

Let’s take a look at the various plant superfoods:

Ascophyllum nodosum

Brown knotweed (Ascophyllum nodosum) is a brown alga common in the North Atlantic. Along with trace elements, it is rich in cytokinin, a phytohormone that stimulates the cell division (cytokinesis) of plants and regulates the aging process. The name alone indicates that this phytohormone activates the metabolism of the plant and leads to improved yield. In 2011, it was shown that an increased cytokinin level leads to an abundance of large flowers and fruits. 

The mechanism behind this is related to the control of the aging process: cytokinin delays the development of plant stem cells into flower cells. As a result, they simply continue to grow before differentiating into flower cells. With more flower attachments, more flowers are eventually formed. Ascophyllum is an excellent supplier of alginic acid. Alginic acid gels with calcium to form calcium alginate, which increases the water retention capacity of the soil and promotes root formation.

The brown Knotentang supports the plant on multiple levels. Although it provides little nitrogen, phosphorus, and potassium, it is a reliable partner in organic farming.

Alfalfa

Snail clover, better known as lucerne or alfalfa, owes its name to its fruiting bodies, whose shape is reminiscent of a snail shell and is cultivated mainly as a fodder plant. An important but hardly noticed feature of this plant is its high content of the phytohormone triacontanol. This phytohormone accelerates cell division and leads to stronger growth of roots, shoots, and flowers. When used as a foliar spray, it increases the concentration of carbohydrates and enzymes in the plant. Lucerne is an excellent source of nitrogen, micronutrients, and trace elements. When alfalfa and Ascophyllum are used, plants react to the increased availability of phytohormones like an athlete to steroids: with more power!

For this reason, alfalfa has been used in American agriculture for many years with numerous products available for purchase. 

Bentonite (silicates)

Bentonite is a valuable tool in organic farming. It consists of at least 60% montmorillonite, a silicate that has a surface area of 400-600m2/gram and expands in water. Due to its high ion exchange capacity, bentonite easily forms the valuable clay-humus complexes, increases the water retention capacity of the soil, and promotes a healthy soil life.

Clay-humus complexes are formed by the binding of clay and humus particles to nutrient particles. The electrical charge of the nutrients is balanced, and thus, the ion pressure on the root membranes of the plant is reduced. Also, the crumbly structure of the clay-humus complexes permanently improves the soil.

Bentonite is also an excellent supplier of silicates. Although silicate compounds are among the most frequently occurring groups of substances on our planet, they are not always available to plants at the same time. Sand, for example, consists mainly of silicates, but hardly dissolves in water and is ultimately not available to plants. Soil microorganisms easily convert bentonite silicates into orthosilicic acid, which is rapidly taken up by plant life.

Silicates play a vital role in the growth of plants because they are built into the cell walls, increasing the resistance to sucking insects and harmful fungal and bacterial infections. The increased availability of silicates improves the absorption of nutrients, increases the plant’s stress tolerance to various environmental factors like heat and drought, and also increases the dry weight of the crop.

Earthworm humus

Plants love earthworm humus! Even a few tablespoons of the stuff can work wonders. Earthworm humus, like vermicompost, has become increasingly popular in recent years, and not without reason. It is the highest quality compost of all and more fertile than all other humus species. It surpasses garden compost, bokashi, and terra preta by far – not to mention commercially produced humus. It is straightforward to make with the help of a worm farm and is an excellent way to recycle organic waste. 

The secret of earthworm humus begins in the digestive tract of earthworms. The worms eat the organic substance decomposed by fungi and bacteria, grind it in their intestines, and excrete it again. Vermicompost contains useful fungi and bacteria and is enriched with enzymes such as phosphatase and cellulase.  These enzymes help plants release nutrients from the soil and break down cellulose into carbohydrates. 

The most significant advantage of earthworm humus over other humus species is its richness in clay-humus complexes. In the intestines of earthworms, there are particularly favourable conditions for their development. In clay-humus complexes, the electrical charge of the nutrient particles is balanced by binding them to a humus particle (e.g., leonardite) and one clay particle (e.g., bentonite). This prevents the soil from becoming salty or over-fertilized with vermicompost! Also, the crumbly structure of the clay-humus complexes loosens the soil and improves its water retention. If you ask yourself now what happens when you feed your earthworms with superfood, then it’s high time for your worm farm. 

Leonardite

Virtually every fertilizer manufacturer has a leonardite product in the form of humic and fulvic acids in its range. The use of leonardite intensifies plant and root growth by promoting the metabolism of plants and accelerating cell division. Leonardite also helps improve photosynthesis by stimulating chlorophyll production. 

Leonardite is produced when organic matter is decomposed and then exposed to high pressure under exclusion of air for millions of years. The expert describes these processes as humification and charring. In the narrower sense, leonardite is high-oxidized soft lignite, which is a by-product of lignite mining. Leonardite is often processed into water-soluble potassium or sodium humate. 

The fields of application of these humate salts are almost inexhaustible. As permanent humus, they improve soils or substrates sustainably, can be used for wastewater treatment, are used as additives in animal feed, strengthen the immune system, promote intestinal health, are used for the treatment of liquid manure, and reduce the emission of greenhouse gases such as methane. The biggest advantage of using leonardite for horticulture is its richness in carbon, as well as humic and fulvic acids. These substances promote plant growth and soil fertility. Humic and fulvic acids are so-called chelates; they can balance the charge of nutrients by cation exchange (cf. clay-humus complexes). This ensures the availability of nutrients and trace elements over a more extended period without the danger of over-fertilizing plants. Humic substances also increase the water retention capacity of the soil and act as a pH buffer. They improve the germination rate of seeds, increase the vitamin and mineral content of plants, lead to thicker cell walls, and thus, to greater resistance to pests and higher harvest weight.

Animal meal

Good thing plants don’t have a nose, because some of these soil amendments can smell horrible. Horn shavings, along with fish, bone, and blood meal are guarantees of success among solid organic fertilizers. Plants love these raw materials because they provide readily available nitrogen, phosphates, calcium, micronutrients, trace elements, and amino acids. The result is robust root, leaf and flower growth, as well as an outstanding aroma of the end product. 

Also, the excellent availability of nutrients, especially nitrogen, stimulates the plant’s hormonal balance. More auxins are formed in the shoot tips, and more gibberellins are released. Both substances are phytohormones, whose effect on plants is comparable to that of hormones on the human organism. The high concentration of auxins in the shoot tips not only improves the vitality of plants in general, but it also enhances the rooting of cuttings. Gibberellins are known in research as steroid hormones, so they rapidly boost plant growth. They have long been used in conventional agriculture in a synthetic form with auxins as growth stimulators, doubling the yield performance of some crops. The production of phytohormones stimulated by animal meal cannot keep pace with the results of synthetic auxins and gibberellins. However, there are significant improvements in vitality and yield.

Blood meal has hardly been used as an organic fertilizer since the BSE crisis, and the use of fish and bone meal is often viewed with suspicion. Blood and bone meal mostly come from poultry and pig farms, while the horn shavings, which are considered harmless and much more widespread, come from cattle. The processing of animal by-products is subject to strict regulations, and a veterinarian regularly inspects the processing companies. The costly approval of a company to process animal by-products has also contributed to the fact that they are hardly used as organic fertilizers. The use of animal by-products in the form of organic fertilisers is a good way of recycling them and a sensible alternative to the incineration of these substances.

Conclusion

You don’t need to enrich your substrate with chia seeds, nor do you need to soak your seeds in pomegranate juice for germination. Simply pay attention to what is in the fertilizers you buy. If you keep your eyes open, you will surely find a product with the inputs mentioned in this article.

The superfood concept for plants can be the beginning of a new way of thinking about fertilizers. Perhaps one day, the principle can be transferred from allotments to agriculture, and we will all cultivate our fields naturally and sustainably, in harmony with nature.