Feed the Plant

Nutrient uptake by plants.

Plants need 17 elements for normal growth. Carbon, hydrogen, and oxygen come from the air and water. Soil is the principle source of other nutrients.
Primary nutrients
(nitrogen, phosphorus, and potassium) are used in relatively large amounts by plants, and often are supplemented as fertilizers.

Secondary nutrients (calcium, magnesium, and sulfur) are also used in large amounts but are typically readily available and in adequate supply.
or trace elements are needed only in small amounts. These include iron, zinc, molybdenum, manganese, boron, copper, cobalt, and chlorine.

Essential Plant Nutrients

Roots take up nutrients primarily as ions dissolved in the soil’s water. The ions may be positively charged (cations) or negatively charged (anions). The nutrient ion soup in the soil’s water is in a constant state of flux as the variety of ions dissolve in and precipitate out of solution.

Humus, clay particles and organic matter in the soil are negatively charged, attracting the positively charged cations (like ammonium, NH4+, and potassium, K+) and making the cations resistant to leaching. Negatively charged anions (like nitrate, N03-) are prone to leaching and can become a water pollution problem. Both ammonium and nitrate are important plant nitrogen sources and are commonly found in salt forms in fertilizers.

The Cation Exchange Capacity, CEC,is a measurement of the soil’s capacity to hold cation nutrients. More precisely, it is a measurement of the capacity of the negatively charged clay and organic matter to attract and hold positively charged cations. CEC is useful in comparing the potential for different soils to hold and supply nutrients for plant growth.

Foliar absorption of mineral nutrients by above ground plant parts including leaves stems and flowers have been reported for over 200 years. Interest however has been mainly since the 1950's. this interest has grown over the years because of the increased costs of fertilizers, environmental concerns about leaching and runoff, a better understanding of how to facilitate the absorption process and a better understanding of plant growth. Minor element deficiencies in fruit have been corrected by foliar applications for 80 to 90 years. More recently over the last 40 years or so, foliar absorption of the macronutrients has also been studied extensively. It is now known that not only nutrients can be absorbed but also pesticides, growth regulators, organic acids and many carbohydrates.
Among the advantages to foliar absorbed nutrients include the fact that they can be rapid and effective, with quick plant response. Because they are so effective they require less fertilizer input by avoiding soil fixation, leaching and runoff. They are applied to the leaf blade and allowed to remain there until fully absorbed. You do not water in. Today we have the knowledge of how plants grow in order to make the most effective use of this technique. Other advantages revolve around the fact that they are effective when the turf has a restricted root system from such things as being closely mowed, periods of environmental stress, seasonal root loss, periods of low photosynthetic output and correspondingly low carbohydrate reserve.

Some nutrients become fixed in the soil and results in low efficiency as a root absorbed nutrients. Foliar applications of nutrients as a supplementary fertilizer are highly effective.

Factors affecting foliar absorption.

Several factors will affect foliar absorption include relative humidity, temperature, pH of the nutrient solution, variety of the turf, age of the leaf, concentration of the nutrient solution, difference in the nutrient compounds(formulations) use of surfactants and the addition of non-nutrient facilitating or carrier-mediated agents.

Humidity and temperature have a direct relationship with absorption of nutrients and as they increase, penetration also increases. The total amount of time the nutrient is in contact with the leaf is critical. Optimum pH is a factor that varies from nutrient to nutrient and most good formulators recognize the need to have optimum pH for the nutrient used.

Many chemical compounds are ineffective as foliar nutrients. For example Shafer and Reed studied a total of 31 organic and inorganic potassium compounds for their efficacy as a foliar fertilizer. Their results showed a broad spectrum in foliar absorption of potassium from both organic and inorganic carriers. Studies from other researchers on many other nutrient compounds show similar results.

Modern Foliars

The effectiveness of modern foliar fertilizers varies significantly and is directly proportional to the quality of the product. Using both organic and inorganic facilitating agents to transport the cations into and throughout the plants has become a very exact science. Harvest Grow uses only the finest colloids in the form of Humates and Kelp nutrients to achieve the best results. The process of building excellent foliar fertilizers is an exacting and complex one.

Many humic and organic materials have the capacity to bind substantial amounts of metals and other cations, and they can therefore exert considerable control over the supply and availability of nutrient elements to plants and in water.

When the metal ion combines with an electron donor, the resulting substance is said to be a complex or coordination compound. If the donor atoms are attached not only to the metal ion but also to each other as well forming a ring, it creates a chelate.

There are good complexes and bad complexes and there are good and bad chelates. Some of the good organic agents used in these products are: humic acids from many sources, fulvic acids, ligno sulfates, amino acids, sugars and carbohydrates and hydrolyzed protein mixes.  Harvest Grow nutrients are biodegradable and available to the plant and the soil micro community as a significant energy source.

Synthetic chelates are used extensively in many agriculture and turf products. Some researchers have reported that they may remain as a residue in the plant tissue or in the soil tying up other nutrients and they provide no additional energy source.  Harvest Grow uses organic chelates keeping them available and biodegradable.


Absorption is only one aspect of a foliar fertilizer. In addition, the absorbed nutrient generally must be trans located throughout the plant. While absorption is a key process in selecting a foliar applied nutrient, the extent of redistribution or mobility of each nutrient in the plant is an important consideration also.

Buyer Beware

There is little regulation over the complexing and chelate foliar industry:
  • The presence of an organic or synthetic chelating agent in the formulation legally makes the product a chelate regardless of how much is in the mix.
  • It does not matter whether there is enough chelating agent in the mixture to chelate all the metals in the formulation or not to be considered a chelate.
  • Any agent that can be shown to cause chelation is considered a chelate, without regard to whether it is stable or not.
  • Unstable chelates that precipitate when mixed with anions, such as phosphorous, are poorly absorbed by the plants and do not translocate well in the plant.
  • The concentration of these complexing and chelating agents in the various formulations need not be on the label.
The best chelating agents are those that are natural components found in the metabolism of the plant and they should compose a high concentration within the formulation.

In his thesis for his PH. D. degree from Michigan State University in 1956 H.B. Tukey Jr. researched Nutritional Foliar Sprays. He made this observation:

"Foliar fertilizers produce quick, visible results and can increase the effectiveness of fertilizer applications to the soil, reducing total amounts of fertilizer applied."

He showed that it works like this:
In photosynthesis; sunlight, carbon dioxide from the atmosphere, water and nutrients, along with chlorophyll in the leaf, combine to produce carbohydrates for plant growth and health. The nutrients in the soil are soluble in the ground water and enter the plant with the water through the membrane of the roots and are carried up the xylem tissue and distributed throughout the leaf where the carbohydrates are produced. The carbohydrates are then distributed throughout the plant and carried by the phloem to the root for storage.

When we apply foliar fertilizer containing the proper nutrients for photosynthesis directly to the leaf, the plant begins to produce more carbohydrates and in the process requires more water. The stomata on the leaf open allowing water vapor to escape, which reduces the water pressure in the xylem tissue allowing more water to flow up the vascular bundle. In turn more water is absorbed into the roots to replace the water moving up. If good nutrition is available in the soil surrounding the root, extra nutrients enter the plan with the water.

If you visualize the plant as a water pump, the foliar fertilizer acts as a primer, priming the pump and bringing more nutrition into the plant.

It is important to remember that the foliar fertilizer actually increases the total uptake of nutrients by several folds over the small amount of foliar fertilizer applied.  Harvest Grow products effectively enhance nutrient uptake by the plant,

Harvest Grow uses natural chelates to enhance nutrient uptake and nutritional value capability of the plant.

Plant nutrient diagram


Our customers know they are getting the very best nutrients for their foliar nutritional program.