Just like animals, plants require a wide variety of nutrients, in addition to pure water, to function at their best. For soil based gardens the goal should be to have soil that not only performs the mechanical functions of providing gas exchange, drainage and support, but that helps to provide the nutrients needed for healthy plants. Well developed compost can provide nutrients that are hard to replicate with other fertilizers and supplements. That said, regular fertilization with quality products can certainly increase plant growth and production. With hydroponics, all plant nutrients must be supplied in the nutrient solution or through foliar feeding. This article will discuss some promising nutritional supplements for plants that go beyond the primary nutrients and list a few recommended products in each category.  

Fortunately, the better fertilizer companies have added micronutrients to their products in addition to the three primary plant nutrients: nitrogen, phosphorous and potassium. For those not using fertilizer, or using a blend that does not contain micronutrients, there are some good products formulated to prevent and correct micronutrient deficiencies. Micronutrients can do some great things for the soil including influencing proper soil pH, improving soil structure and water retention and positively influencing the level and activity of beneficial soil microorganisms. They also aid plants to better use primary nutrients. Because of these benefits, and particularly if one has experienced problems associated with micronutrient deficiencies like blossom end rot or tip burn, it may be good insurance to experiment with micronutrient supplements. Two possible products are:

Botanicare Cal-Mag Plus

A plant supplement designed to help with calcium, magnesium and iron deficiencies in nutrient fertilizer programs and hydroponic nutrient liquid concentrated formulas. It prevents blossom end rot in plants such as tomatoes and peppers and tip burn in lettuce by serving as a catalyst for the major elements to work in symbiosis with one another. For additional information visit http://www.americanagritech.com/

Technaflora MagiCal

An enriched formulated blend of magnesium, calcium and iron, that promotes plant growth for both soil and soilless gardens. Incorporated in regular feeding programs it increases flower bud absorption and improves the nutritional quality of plants while correcting nutrient related plant deficiencies. In addition to correcting nutrient deficiencies, it also accelerates protein syntheses, maintains high starch content in crops, improves the density of fruit and the production of essential oils, creates lush and greener foliage, and maintains a healthy root system. Designed for universal application, it is for gardens that require bolstered levels of magnesium and/or calcium. For additional information visit http://www.technaflora.com/.

B Complex vitamins have been shown to help plants overcome stressful growing conditions, increase nutrient uptake and increase disease resistance. Some formulations may also contain other vitamins, amino acids and minerals. The use of B vitamins may be of most benefit when transplanting and/or during early season root formation. Two possible products are:

Technaflora Thrive Alive B-1

Stimulates rapid and lush vegetative growth, and will ensure the success of floral crops by promoting flowering during blossoming. It contains vitamins and nutrients, which are cultured in sea kelp. It facilitates root development for both cuttings and established root systems, while protecting plants from transplant-related shock. Safe and easy to use, it can be applied as a soil drench, rejuvenator, or as a foliar spray. For more information visit http://www.technaflora.com/.

VitaMax™ and VitaMaxplus™

A specially formulated to encourage better root development, larger buds, blooms, fruits and flowers. It contains essential macro and secondary nutrients to help increase plant development at the blooming and fruiting stages and to reduce plant stress during transplanting, inclement weather etc. VitaMax Plus™ has the same stress-relieving properties as Vitamax™ plus a slightly higher concentration of ingredients making this product an ideal supplement to use during heavy flowering. For more information visit http://www.getgreenstar.com/.

Silicon (Si) is abundant in most soils. It is readily taken up by plants and is often present in relatively high concentrations in plant tissues. The beneficial effects of adequate Silicon may include decreased susceptibility to fungal pathogens (and insects), increased stress resistance, improved nutrient uptake and increased growth. One possible product to consider is:

Botanicare Silica Blast

Helps strengthen plant tissue helping plants flourish in adverse environmental conditions such as heat, drought, and frost. It is designed for use in container gardens or soilless hydro-gardening applications. For more information visit http://www.americanagritech.com/.

In addition to being a good source of organic nitrogen and potassium, kelp contains vitamins, minerals, carbohydrates, enzymes, amino acids and growth hormones necessary for optimum plant growth. Kelp stimulates soil bacteria to release plant nutrients already found in the soil and contain cytokinins which directly affect the ability of plant roots to absorb nutrients. It is believed to increase a plant’s stem strength helping the plant handle the stress of wind, rain, drought, high temperatures, and frost. Several possible products to consider are:

Maxicrop Liquid Seaweed

Our basic pure seaweed extract’s natural growth stimulants initiate cell growth and cause vigorous growth of both root and stem. The trace elements that Maxicrop Liquid Seaweed contains are important at this stage—in enzymes, as activators of enzyme systems, and as stimulants. For additional information visit http://www.maxicrop.com/.

Neptune's Harvest Kelp Meal

Neptune's Harvest Organic Kelp Meal is suitable for all crops and applications, and can be mixed with most soil conditioners and fertilizers. It can also be incorporated into potting soils, seed and transplant beds, as well as composting material. For additional information visit http://www.neptunesharvest.com/.

Neptune's Harvest Seaweed Plant Food

This is an organic product containing over 60 naturally occurring major and minor nutrients and amino acids.  Its growth promoting substances (Auxims, Cytokinins, Gibberellins) enhance plant development, color and vigor. For additional information visit http://www.neptunesharvest.com/.

Technaflora B. Seaweed

An optimal growth stimulant for all your plants made from 100% pure kelp (Macrocystis integrifolia) and is an organic way for growers to supplement their current feeding programs.  It is concentrated, and must be diluted with water for use in irrigation solutions or as a foliar spray. Ideal as an additive for organic tea mixtures, it is also a superior soil tonic, and can be added to the hydroponic reservoir. For additional information visit http://www.technaflora.com/.

This is a big part of the good stuff that composting aims to develop. These complex molecules are formed as organic matter decays, and occur naturally in soils, peat, oceans and fresh waters. Humic acids are the primary extractable component of humic substances. Fulvic acids are also extracted from humic substances and may be more plant active than humic acids due to their higher oxygen content and abundance of carboxyl groups. Humic acids enhance the nutrient richness of soil and they are believed to increases the permeability of plant membranes promoting the uptake of nutrients resulting in stronger, healthier, better producing plants. For more information on applicable products visit these websites:

Blackjack Liquid Humic Acid and Golden Humic Acid Extract

These products are a proprietary premium blend of 100% humic minerals from leonardite in an aqueous base. They are fast acting and have a guaranteed source of phosphorus as available phosphate P205 (0-2-0). The products may also have a natural source of over 70 plant-derived trace elements, carbon, enzymes and amino acids that contain naturally occurring organically infused microscopic soil known as nano-nutrients that are not listed or guaranteed on the label. For more information visit http://www.blackjacksoil.com/.

General Hydroponics Diamond Nectar

Diamond Nectar applies the magic of the smallest available humic acids to nutrient rich hydroponic environments by grabbing these nutrient minerals and transporting them into plant roots for faster growth and higher yields. It enhances your nutrients in order to optimize the health of your plants and the quality of your crops. For additional information visit http://www.generalhydroponics.com/.

General Hydroponics Rare Earth

Rare Earth is derived from ancient seabed deposits of pyrophylitic clay that are blended with fulvate ore. By slowly releasing silicon, humates, and organic rare earth minerals, Rare Earth allows a crystal matrix to develop within growing plant tissue that protects the plant from heat stress and nutrient extremes by generating a protective silicon shield. This also deters fungal disease and reduces susceptibility to insect damage by "hardening" the plant. Use Rare Earth by blending it with rooting media, and either top-dressing around the plant stem or adding it directly to nutrient solutions. For additional information visit http://www.generalhydroponics.com/ 

Neptune Harvest’s Super Humate

Super Humate contains vital elements for healthy soil in an easy to apply liquid form. It provides valuable plant elements, holds water in the soil, feeds the living organisms in the soil, and releases locked-up nutrients for plant growth. For additional information visit www.neptunesharvest.com.

Technaflora Concentrated Liquid Humus

This product is a natural and organic source of concentrated essential nutrients, vitamins and trace elements. It is a 100% organic solution of 15% technical humic acids extracted as salts from a soft coal called leonardite. It increases the permeability of plant membranes and the buffering capabilities of the medium, promoting the uptake of nutrients. With the systematic application of Liquid Humus, the results are healthier, lusher plants with faster growth, more vigor and larger yields.. For additional information visit http://www.technaflora.com/.

The field of human health supplementation is full of products and claims of increased performance and plant nutritional supplementation is not far behind. With the supplements discussed in this article and others, it may be worth a side-by-side experiment to see if the addition to ones individual soil or nutrient solution has a positive impact on plant growth and performance.

Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a Senior Staff Writer for Garden and Greenhouse Magazine. You can contact him at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it