Pottstown’s Shade Tree Program

Downtown Pottstown is mostly asphalt and rooftops. There’s not much green, even in the summer. As a result, cities and towns like Pottstown are often much hotter than the surrounding suburbs.

Hot roofs and pavements, baked by the sun, warm the air blowing over them. The resulting urban "heat island" causes discomfort, hikes air conditioning bills, and accelerates air pollution.

A study by four energy experts, reported in the MIT Technology Review, concluded that the two least expensive and most effective methods to reduce energy consumption in cities and towns are:                            look familiar?

* Use lighter colored roofs and pavement.

* Plant lots of trees.

Pottstown does not have the huge lawns of the suburbs or the open fields of the countryside. We are densely populated, with houses and other buildings placed close to each other and to the street. We have lots of paved surfaces and rooftops, especially in the older parts of town.

If we want to bring nature into our town, we must do it with shade trees. Even big cities can be green and shady if they plant hundreds of big trees.

Pottstown has 3,300 street trees. Street trees are publicly owned shade trees located in grass planting strips between the curb and sidewalk, or in pits within the sidewalk itself. These trees greatly enhance the environment and quality of life in our town:

* Trees fight global warming by absorbing greenhouses gases like carbon dioxide from the air.

* Trees filter pollutants from the air. Street trees can attract and remove up to 75 percent of airborne dirt, dust, pollen and smoke from the air, binding it to their leaves until the rain washes it back to the earth.

* Trees lower ambient temperatures, making Pottstown cooler in the summer. One mature tree provides the cooling equivalent of five 10,000 BTU air conditioners running 20 hours daily.

* Trees reduce energy consumption by reducing the need to run air conditioners.

* Trees soften the urban environment. They unify disparate buildings and screen eyesores.

Many of Pottstown's street trees were planted between 1984 and 1989 by Trees Inc., a private, non-profit organization. The photos below show the difference trees have made:         Before                                    After

When we build houses, our indoor living space is divided into different rooms.

Historically, when we built our cities and towns, we made our streets into outdoor rooms, with the walls formed by the buildings on either side of the street, like Delft, or Paris, or Pottstown.

Delft

Paris

Pottstown

Consider the most magnificent of buildings: the cathedral. Pillars on each side of the sanctuary are stone imitations of tree trunks, and the latticework ceilings are stone imitations of tree branches

Our outdoor living spaces can become cathedrals of green, with the tree canopy creating a "cathedral ceiling" over our streets.

To form a canopy over our streets, and to cool our houses, trees must grow to a height of at least 40 feet. Trees that grow too low block the way, make dark passageways, and obstruct windows and signs.

    Too low                                                    Correct height

These trees are trimmed to create a high canopy and let in plenty of light.

In Paris, trees have their lower branches removed at an early age.

These trees were planted on the 300 block of Walnut Street by Trees Inc. in 1984. They have now grown tall enough to form a "cathedral ceiling" over the street. The lower limbs have been removed, so the canopy is least 16 feet above the street.

With the approval of the Pottstown Shade Tree Commission, a private non-profit corporation called Trees Inc. has been regularly trimming Pottstown's younger street trees. These trees are being "elevated" – that is, their lower branches are being removed - as the trees grow.

Our goal is that once a tree reaches a height of more than 30 feet (well above the second story of a building), the lowest branches will be 16 feet off the ground.

Property owners have four major complaints about street trees:

Tree roots lift sidewalks

Tree roots sometimes get into sewer lines

Trees drop leaves which must be raked and occasionally cleaned out of gutters

Trees sometimes drop "sap" that falls on cars and attracts bees

Tree roots extended a great distance laterally – twice the width of the tree canopy – but they are very shallow. About 90% of a tree's roots are within the top 30 inches of soil. That means they sometimes lift sidewalks. Lifted sidewalks are part of the price we must pay to have street trees in Pottstown.

The tree pit is the area removed from a sidewalk for the tree. The larger the tree pit, the healthier the tree will be and the less likely it is that sidewalks will be lifted. Except in Pottstown's downtown commercial district, there is no reason any sidewalk needs to be more than 4 feet wide.

Tree pits can be expanded by removing excess concrete to form a planting strip to allow tree roots space to grow and reduce the chance of a lifted sidewalk. It also allows rain to permeate the ground.

This tree pit is too small.

If necessary, sidewalks can be reduced to 3 feet wide.

Brick can provide a walking surface around the tree.

When tree roots lift a sidewalk, the best solution is ...

...to reduce the width of the sidewalk.

If you are installing a new sidewalk, you can go around a tree, or create a large tree pit covered with bricks that can be removed as the tree grows.

If you don’t have room to go around tree roots, you can "shave" the roots with a hatchet by removing small roots and notching large ones about 3 inches below ground level to allow room for a new sidewalk over the roots.

Notch the root to make room for the new sidewalk

But don’t sever the root! You’ll kill or destabilize the tree!

When pouring a new sidewalk, you can shave down large roots with a hatchet or root grinder to allow 3 inches for pouring concrete or putting down bricks

Don’t sever big roots! You could kill the tree, or destabilize the tree so it might fall over in high winds or a storm.

When a block of cement in a sidewalk is lifted by tree roots, the "lip" creates a tripping hazard.

The lip can be covered over with patch cement like Top ‘n Bond or Sacrete to fill the joint.

In severe cases, the cement block can be removed and filled with patch cement or blacktop. The borough prefers Sacrete or patch cement to blacktop.

When installing new curbing, use a metal plate adjacent to the tree.

Plates in various lengths are available from Pottstown Metal Welding Inc.

Blacktop

Blacktop is used to eliminate ripping hazard.

Patch cement

Patch cement is preferred to fill the gap in a lifted sidewalk.

Slate

This property owner used pieces of slate to patch a lifted sidewalk

Tree roots will not penetrate a sound sewer line. If tree roots enter a sewer line, it is because the pipe is faulty. When a sewer pipe breaks or leaks because of age or improper installation, nutrients and water ooze into the surrounding soil. This will attract any nearby roots, which will thrive and may even enter the defective pipe and block the passage.

Many older sewer pipes in Pottstown are made of clay, which eventually cracks because of soil settlement or earth tremors. Modern sewer pipe is made of iron or plastic. Problems can be prevented by:

* Proper construction of new sewer lines, including tight joints and a firm soil base.

* Repair or replacement of defective sewers. Repeated blockage may indicate a damaged pipe.

90% of a tree's roots grow in the top 30 inches of soil, well above sewer pipes, which are generally buried 6 feet or more below the surface.

Even so, the only way tree roots can enter a sewer pipe is if there is a break or leak in the pipe, just as the only way rain can enter a building is through a leaky roof.

Trees drop their leaves in the fall. Some people find raking leaves annoying. Others welcome leaves as a sign of the changing seasons. Children particularly love leaves. Falling leaves enrich the environment and give people a reason to get outdoors in the autumn and enjoy nature.

In 1954, Pottstown Council created the Pottstown Shade Tree Commission and enacted the borough's Shade Tree Ordinance. Under the ordinance, the Shade Tree Commission has jurisdiction over all street trees in Pottstown.

The written permission of the Shade Tree Commission is required to plant, trim, or remove a street tree.

The ordinance requires that street trees shall be maintained by the adjacent property owner. At the request of the Shade Tree Commission, dead or dying trees must be removed by the adjacent property owner, and the stump ground to a depth of 2 feet to allow for a replacement tree. The Shade Tree Commission may also require adjacent property owners to trim trees with dead or low-hanging branches.

This is the usual arrangement among most Pennsylvania municipalities. A small number of boroughs, such as Wyomissing and State College, pay for all the costs of planting, trimming and removing street trees.

At present, Pottstown government allocates $20,000 annually for street trees in Pottstown. This is an expenditure of $1 per resident, which is 50% of the minimum recommended by the National Arbor Day Foundation.

If a property owner is requested to remove a dead or dying tree, and does not do so after receiving two notices, the borough will remove the tree and may place a lien against the property to recover the cost.

People who illegally remove a street tree must pay the replacement cost on an inch-per-inch basis. If a person illegally removes a tree with a 12-inch diameter trunk, for example, the borough will plant four 3-inch diameter trees to replace it and bill the offender for the cost of those four trees. Failure to pay the bill can also result in a lien placed against the offender’s property.

In 1983, a non-profit corporation called Trees Inc. was established to encourage the planting and maintenance of street trees in Pottstown. Using a maintenance fund from Borough and private donations, Trees Inc. performs routine maintenance of street trees in Pottstown and plants new trees to replace ones that have died.

Pottstown lacks the new houses and large lots of the suburbs. To attract and retain middle class families, the borough must create and maintain desirable neighborhoods. Despite the occasional problems they cause, trees are essential to keep our town green and beautiful. Thanks for your help.

A Pottstown street tree can live 75 years or more. For example, the trees in front of the Pottstown Middle School and The Mercury office are about 70 years old. Each year a tree grows, it becomes more valuable to the community. One mature tree 70 feet high and 50 feet wide provides more environmental benefit than scores of young trees just starting to grow.

A tree whose trunk is 12" inches in diameter provides more environmental benefit than 16 trees with a 3" diameter trunk.

Trees cool our town and absorb pollutants from the air.