Fertilize to Encourage Healthy Growth
As the soil warms-up we are seeing more flowers on the trees and shrubs. This is a good indicator that it is time to apply fertilizer to tree and shrub beds to encourage healthy growth this spring and summer. If you haven’t taken a soil sample in the tree and shrub area, then it’s a good time to do that now. Knowing what the soil needs will help select the right fertilizer for the area.
Many soil samples I have seen over the last couple of years have been low in potassium (the third number on the fertilizer analysis). In the absence of a soil test, I usually recommend 10-10-10 as a good fertilizer to apply. However, in many cases the plants may only need nitrogen (the first number on the fertilizer analysis). Many of our coastal soils have a neutral or slightly alkaline soil pH, making ammonium sulfate (21-0-0) fertilizer a good choice as it will lower the pH of the soil slightly. This can be applied at 5 pounds of fertilizer per 1,000 square feet of bed area.
The best option for applying fertilizer would be to apply what is recommended on the soil test report. Healthy trees will be able to withstand some insect and disease damage.