Fertilizing Plants now.
Hi - The best time to fertilize trees and shrubs is between late October and early December, or between late February and early April. The need for fertilizer should be based on soil test results. Refer to our website for more details. https://extension.umd.edu/hgic/topics/fertilizing-trees-and-shrubs
Here is information on how to do a soil test. https://extension.umd.edu/hgic/topics/soil-testing