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Caring for Trees

Yard Tools

Pruning Your Trees

Many people "top" trees because the trees grow into utility wires, interfere with views or sunlight, or grow so large that they worry the landowner. Sometimes homeowners believe that cutting the top off of the tree is the answer, but this process is many times self-defeating.

Cutting the main branches back to the stubs is incredibly detrimental to the health of the tree, and cutting more than 1/4 of the tree's trunk and upper branches may kill the tree. The ugly, bushy, weakly attached limbs that grow in place of the topped off area of the tree grow back higher than the original branches, blocking any view initially gained or growing right back into the power lines that were meant to be cleared.

Proper pruning can remove excessive growth without the problems topping creates. Many arborists say that topping is the worst thing you can do for the health of a tree. It starves the tree by drastically reducing its food-making ability and makes the tree more susceptible to insects and disease.

When pruning or cutting your tree, it is important to remember how a tree should be maintained to continue a healthy life in your yard and neighborhood.

Yard Tools

Another particular danger that often befalls trees in residential and city neighborhoods is damage done to trees by weed wackers and lawnmowers. When cutting along a tree, it is important to avoid damaging the bark of the tree. This part of the tree helps conduct water to the higher branches, therefore damaging it weakens the tree and invites disease.


Mulching is an important aspect in maintaining healthy trees in ones yard. A good layer of mulch can be a tree's best friend, insulating soil, retaining moisture, preventing weed growth and soil compaction and reducing lawnmower damage to the lower half of the trunk. Mulch is also asthetically pleasing, giving a yard a pleasant atmosphere as well as protecting the tree.

Mulching reproduces the conditions available to a tree on the forest floor. Ample fertilization available from the decaying mulch reproduces similar conditions in wooded areas. Considering this, a tree owner must attempt to cover good portion of the root structure of the tree with mulch.

The owner should remove all grass within 3 to 10 feet in diameter, depending on the size of the tree. Wood chips or bark pieces should then be added 2 to 4 inches deep within the circle prepared around the tree. Mulch should not physically touch the trunk of the tree, but should fill the area immediately around it without touching the trunk.

Watering Your Trees
The most important aspect of keeping a healthy tree is watering your new tree. Watering your tree with approximately 10 to 15 gallons of water once per week from March until the end of October. 10 gallons of water is the equivalent of 10 minutes of water running slowly from your garden hose.

When the weather is excessively hot, a street tree will need at least15 gallons of water each week, applied in 2 separate waterings: 10 gallons one day and 5 gallons a few days later. If your tree pit does not have a drain grate protruding from the soil, pour the water into the crack running between the curb and the sidewalk. Cultivating the soil allows water to seep to the roots, and adding mulch will conserve soil moisture.

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City Planning
200 Ross Street
Fourth Floor
Pittsburgh, PA 15219
(412) 255-2200