When to Fertilize Your Tree
It’s a good idea to fertilize a growing tree throughout the year. During the spring and summer you should provide the greatest amount of nitrogen based fertilizer. As the tree ages, it’s best to provide several light fertilizer applications. You might need to do a soil test to determine the potassium (K), nitrogen (N) and phosphorus (P) levels. Read fertilizer labels to learn the correct ratios and the application rate for trees.
How to Fertilize Your Tree
It’s a common mistake thinking you must remove mulch to fertilize your tree(s). You don’t. Just scatter the fertilizer under the drip zone of the tree. Don’t allow the fertilizer to touch the tree trunk. On average apply .10 to .20 pounds of nitrogen for every 100 square feet. Remember to read the label. Make sure that you keep solid/concentrated fertilizer away from the stems and leaves. Make sure that you provide adequate water so that the fertilizer gets into the soil. This will also prevent burning the roots. Unless your tree is deficient of phosphorus or potassium it’s best to stick to a higher nitrogen ratio fertilizer. N-P-K rates of 27-3-3, 18-5-9, or 16-4-8 work well.
Organic fertilizers are plant or animal based and have a slower release of their nutrients because they have to be decomposed by the microorganisms in the soil. While they take longer to work they are much easier on the roots of the plants.
Organic fertilizers are a bit harder to find than inorganic fertilizers and they are often more expensive, but they are far less harmful. Bone meal, cottonseed meal, chicken litter and manure are the best organic fertilizers.
Inorganic fertilizer is less expensive and the easiest to find, which is why it is the most commonly used fertilizer on trees. Inorganic nitrogen fertilizer included sodium nitrate, ammonium sulfate, and ammonium nitrate.
Fertilize your trees regular to help keep them healthy.