Usually this time of the year we are having significant rain. This year we are not having any rain. The street trees and most large trees are being adversely impacted.
Even in a good year of rain, heavily pruning a tree is not recommended except for a few unique specimens. This year, without rain, heavy pruning of large existing trees may kill the tree.
Google is very helpful when it comes to pruning trees. First, identify the tree and then reference on how to take care of that species—it usually includes information on whether to prune or not. Some trees can be heavily pruned like fruit trees but others like Crape Myrtle (Lagerstroemia indica) will be seriously stunted and after repeated years of cutting back will die. There is even a name for it online: Crepe murder.
Even the company that was hired by the City of Morgan Hill to prune the street trees this year were not clear on pruning, for example; typically Magnolia trees (Magnolia grandiflora) are not pruned at all and they were pruning out all of the “crossing” branches, ultimately thinning this slow-growing tree out so much that it lost its beautiful shape. Each tree has a method of pruning and some, like the Magnolia, require none and pruning can damage the tree forever.
The fire department requires removal of branches up to six feet, not reducing the top of the tree. Cut the lower branches and bring the beginning of the tree canopy up to encourage a larger tree providing shade and habitat for animals and birds. Shade helps the world stay cooler.
Parking lots are required to have trees shading every six stalls to prevent a heat island effect, since paved areas substantially increase the heat, not just in the parking lot but in the surrounding neighborhood. The difference between heat on the asphalt under a tree and in the full sun can be as much as 15- 20 degrees. Around your house and on the street, trees can drop the temperature to a level that can significantly reduce or eliminate the cost of air conditioning.
There are a lot of people on Nextdoor who will help identify a tree that you post a photo of. Some can even identify trees without leaves, just based on the structure.
So before you cut or ask an unlicensed landscaper to prune your trees, understand what the tree is and how to care for it. Reach out to online forums…there are a lot of people out there who will be glad to help. And don’t forget to water deeply even now in winter, and if you can, work with an arborist to understand how you can not only water but fertilize for maximum tree health.
Lesley Miles
Morgan Hill
