Why is it that if I apply plain fertilizer to my lawn and don't wash it from the foliage it burns the foliage.
But if I apply weed and feed I leave it on the foliage without it burning?
After I apply it when and for how long is the fertilizer available for the plants.
Thanks in advance
In short - concentration of the fertilizer salts - one dilute, the other concentrated
dry types, depends. Some are not taken up below 45 degrees (it's either urea or ammonium nitrate), others as soon as water brings the dilute inorganic salts to the root hairs.
First of all fertilizer is not food for plants. People who think they feed trees should feed the plant real good and place it in a dark closet and see how long it can be fed. Plants manufacture their own food. Animals do not. Their are exceptions like the Ghost Flower which has no chlorophyll. It gets its food from other plants. People who call essential elements food and nutrients have no understanding of photosynthesis. When you apply ammonium nitrate it can burn plants. Remember when we say fertilize that there are 17 essential elements. Most people only care about 3 elements. N-P-K. What about the requirement of the plant for the other elements? Beware of product pushers.
You may find some useful information here.
John A. Keslick, Jr. Tree Biologist
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