As your plants may be looking a little sad or dwindling down as temperatures cool, some of you may be wondering if you should fertilize these plants. When it comes to fertilizing trees and shrubs at this time, the answer is NO. Fertilizing woody plants (trees and shrubs) while they are still actively growing in late summer will result in a flush of growth that may not have time to harden off before the winter hits.
Typically, the best time to fertilize woody plants is in early spring or later in fall after the leaves have fallen off or shoot growth has ceased. Apply granulate fertilizer at the ground level using a spreader or apply a light layer of compost. Cover all of the area below the canopy of the tree. Keep in mind, if your trees and shrubs are looking healthy you do not need to fertilize at all. Typically a lawn fertilization program will supply enough nutrients for the woody plants that surround it. Also, mature woody plants are able to use their extensive root system to get sufficient nutrients.To learn more about fertilizing woody plants and fertilizer application rates and methods please click on the link below to review a great publication from University of New Hampshire. Fertilizing Trees and Shrubs