Tree Planting and Care 101: Mature Tree Care and Pruning

A newly tranplanted has one primary need: water.  As a tree grows taller, its needs change. For example, it will be less sensitive to drought, but may need more attention to maintaining healthy soils and a sound branching structure.  A professional arborist will be able to help with long-term care so that the tree can live out its full lifespan.  Meanwhile, below are some tips you can follow to care for your tree.

Are you a business looking to enhance the street trees in front of your property? Visit our Trees and Retail resource page.


Guidelines
  • Take good care of the soil: follow the guidelines from the soil care section.
  • Examine the tree at least twice a year: in summer, look at the health of the leaves and lower branches; in late fall, after the leaves have dropped, look at the structure of the branches.
  • As upper branches form, lower ones get shaded out, begin to die, and fall off. Although this is a natural process, in your yard these lower branches will need to be pruned properly to control their fall. Most pruning should be done by your arborist during the dormancy period, in winter.
  • Storms may damage trees. Your early work in selection, placement, and care will help protect the tree. A healthy tree is a strong tree.
  • If there is storm damage, have your arborist take care of it. A broken branch improperly pruned can cause the tree to rot inside, creating a cavity that will weaken the structure of the tree, making it more vulnerable to future storms.
  • Construction, even simple walkway paving, may damage trees. Take precautions to protect the trunk, branches, and roots. Damage to the roots, from either cutting or compaction if equipment is stored or driven over them, can be devastating for the tree in the long run, and may cause failure years later. Also, make sure construction does not remove a water source for the tree, or change the level of the soil.
  • If a tree is doing poorly (leaves do not look healthy, fungi is forming, etc.), consult your arborist to diagnose the problem. It may be from a living organism, like an insect or plant disease, or it may be a physical problem, like too much salt. The professional will know whether something can be or needs to be done about the problem. Some problems go away on their own or are not serious; some can be solved by changing management practices; some need to be treated.
  • During a drought, do provide extra water for the tree, 15-20 gallons per week. Be aware that a tree may drop its leaves during a drought but may still recover.
  • Even if you do not identify a problem, have your arborist inspect the tree once every 10 years or so. They may be able to see hazards you may not have recognized and make suggestions for improving care.
  • Do not fertilize the tree unless a soil sample indicates that there is some missing nutrient.  Get more information on soil testing.
  • Do not lock bikes to trees or leave decorative lighting on past February.

Remove supporting wires if they are left on more than one year after planting.


Pruning

As a young tree begins to take its mature form, it may require pruning. Pruning tools are sharp and dangerous to use. Pruning done incorrectly can endanger both people and weaken the health of the tree. For a tree in your yard, consult your arborist. Never allow anyone to "top" the tree to reduce its height. Most concerns can be addressed with alternative, proper pruning techniques. Visit the Arbor Day Foundation website for simple pruning instructions.

Street trees and Greenstreets are pruned by the Parks Department. If you want to learn how to prune and earn a certificate that would allow you to prune young NYC street and Greenstreet trees, take the Citizen Pruner course from Trees New York. Only trained professionals should prune mature trees.