Fertilizing older dogwood trees
We have somewhat stressed dogwoods, about 48 years old, that are going to be trimmed and a few good-size branches removed. For years they have been professionally cared for. When should the trees be fertilized--before trimming, at the time of trimming, or after trimming? Thank you.
Baltimore County Maryland
Mature trees usually do not need fertilizing at all. They receive nutrients from the breakdown of lawn clippings and mowed leaves, which mimics nature's fertilizing. Also, when we fertilize our lawns, some nutrients reach the tree's root zone, which can extend out to 1 1/2 times the height of the tree. Decaying mulch also provides some nutrients and soil amendments.
If you fertilize, use a slow release fertilizer or apply a composted product. Before, during or after pruning will not make an appreciable difference.
Here is our webpage on fertilizing trees: http://extension.umd.edu/hgic/topics/fertilizing-trees-and-shrubs