Important Tips for Foliar Feeding

The value of foliar feeding was proven by research at Michigan State University many years ago.  A project partially funded by the Atomic Energy Commission used radioactive tagged nutrients to prove that a plant can feed through the leaves.  In fact, they proved that it is four to thirty times more effective to feed a plant that way as far as the amount of nutrients necessary to do the same job and there is no risk of ground water contamination.

While we believe foliar feeding is useful and effective in correcting deficiencies, we use it primarily to increase yield and quality by overcoming the limitations of the soil and its ability to transfer nutrients into the plant.

Best Time To Foliar Feed

Between 7 and 10 am or after 5pm when the plant’s stomata (the small openings on the leaves) are open.  Stomata has very little role to play in foliar absorption of nutrients.  All nutrients diffuse through minute pore (1nm size) on the cuticle membrane.  Cuticle is the outermost layer on the leaf surface, which prevents excessive water loss.  The cuticular pores are lined with intense negative charge that favours movement of potassium, calcium, magnesium, trace elements and ammonium ions.  Urea diffuse easily because it is an electrically neutral molecule.  Ions such as phosphates, sulphate, nitrate move slowly, hence multiple applications are required.

If the temperature is 25°C or above at 7am don’t bother to spray, as it will have little effect due to rapid evaporation of spray droplets.  The best temperature is around 21ºC.  If the weather is very hot and dry, then you may have to spray between 2 and 4 am.  The surface winds should be less then or equal to 8 km/h to prevent spray drifts.

All foliar sprays should have a pH between 4 and 6 where possible.  Usually you want sweeter (alkaline) sprays for young plant growth and sour (acid) to make fruit, grain, ears etc.

If foliar feeding is done correctly, you should see visual results in approximately 48 hours.  Always mix sprays as thoroughly as possible; apply in as fine a mist as possible.  The ultimate sprayer is a mist sprayer that homogenizes the solution and applies it in a fine mist across a large swath.

The “law of little bits” always applies to foliar feeding.  It is better to spray small amounts of material more frequently than it is to drench large amounts of material.  Always be careful of burning the leaf when bright sun is allowed to shine on the spray.  Many  Spraygro Products have an organic chelating agent therefore the inclusion of a wetting agent may not be required as the chelating agent acts as a wetting agent.  It is also important to use a wetting agent with most sprays to “spread” them out preventing beads of water from forming on the leaves and to provide more even coverage.


  • Counteracts adverse soil conditions; salinity, alkalinity and acidity that locks out micronutrients.
  • Correct single or multiple deficiencies of nutrients.
  • Rapid plant growth and increased returns.
  • Enhanced absorption of soil applied nutrients.
  • Nearly 95 to 100% utilization efficiency of nutrient applied
  • Correcting critical nutrient ratios to optimize growth.
  • Activates enzymatic systems of the plant, quick translocation of nutrients from leaves to the growing points.

This year more than ever, you should consider foliar feeding your crop!

We manufacture a complete and full line of foliar sprays.



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