When should evergreens be fertilized? My evergreen garden book says...

Asked October 14, 2014, 2:47 PM EDT

When should evergreens be fertilized? My evergreen garden book says October….My local garden store says spring..I have already fertilized some of these trees & shrubs….What can I do to repair the damage..if any. Mary Loy

Oneida County New York

3 Responses

Dear Mary,

Thanks for contacting us. Before you decide to fertilize, have a simple soil test done: http://www.cceoneida.com/home-and-garden/soil-testing-and-diagnostic-services/ A soil test will indicate what nutrients, if any, are needed. Trees and shrubs rarely need chemical fertilizers. Fertilizing when it is not needed is expensive, and contributes to contamination in water run-off into lakes and streams.

If a soil test indicates fertilizing is advisable, it is usually best to fertilize evergreens in early spring when new growth is starting.

My recommendation as a horticulturalist is generally to avoid chemical fertilizers. (We have a little saying: Feed the soil, not the plant.) Instead, apply mature compost in spring, fall, or both. (Compost can actually be applied at any time since it will not burn the plants.) This can be purchased, home-made, or available from some municipalities. Spread about 1/2-inch compost across the entire root zone of each plant. Do not till it in, but do cover it with an organic mulch such as chopped dry leaves, wood chips, or grass clippings. In addition to building healthy soil, this practice will conserve moisture year-round.


However I have already fertilized some of the plants….will this cause damage? Mary

Dear Mary,

Your plants should be fine. Fertilizing late in the summer sometimes results in winter burn on new growth that does not have time to harden-off. There will be no permanent damage, and no harm done.