Need for Fertilizer for Established Shrubs and Trees
Do established shrubs and trees, which look healthy, need routine fertilization? I am involved with Tru-Green and I dropped the fertilization part of their program. But I wonder if my healthy shrubs and trees should actually be fertilized, and, if so, how often per year? I felt when I used their 2X/year fertilization program that my plants were actually getting too big, or, should I say growing too much so needed too much pruning Thank you.!
Baltimore County Maryland
Established trees and shrubs do not need to be fertilized. In nature, trees and shrubs are fertilized by the fallen leaves and other plant debris (and animal debris) that decomposes under the plants. Artificial fertilization can over-stimulate growth and actually makes the growth more tender and attractive to pests. Also more nutritious for them! And, yes, fast growth means plants that require more care and a million pruning cuts which are openings for disease.
If you fertilize your lawn (a whole different issue), some of that fertilizer probably passes through the turf to tree roots below. Mowing the lawn and letting the grass clipping remain and decompose is a recommended way to naturally fertilize the soil. Also, mowing (mulching) fallen leaves in autumn as much as possible, and leaving the pieces to decompose feeds the soil. (Of course, with heavy leaf fall, turf can't be smothered by too much.) Fallen leaves can also be left under shrubs or trees, as long as they don't smother desirable plants. Applying composts, mulch or yard debris under trees and shrubs and letting it decompose--all these enrich soil and actually improve the structure of soil, something that chemical fertilizers can't do and making chemical fertilizers unnecessary.
Thank you SO much! Is there ever any reason to fertilize an established shrub. I don't mean my whole yard but, e.g. my cherry laurel look skimpy in some cases. It may be because they have scale (in some cases), however, and the problem is not lack of nutrients?
If a shrub has had a problem (such as a scale infestation) it would be okay to give it a little boost with either some fertilizer or compost in the fall.