In addition to the white pine, Eberling would also recommend a couple of nonnative Maryland varieties. The Norway spruce and white spruce retain their lower branches longer than a white pine, he said.
Hemlock trees also can be good windbreakers. But now is probably not a good time to plant one, as hemlock in certain spots along the East Coast, including Washington County, are suffering infestation by the hemlock woolly adelgid, said Eberling and Annette Ipsan, horticulture extension educator for Maryland Cooperative Extension in Washington County.
Eberling said the bugs cling to the bottom of the needles, from which they suck out the juice. This can kill the hemlock unless caught early and treated annually.
Any deciduous tree will provide shade and cool a house during the hotter months, while letting sunlight through its bare branches during winter months to help heat the home, Eberling said.
Large deciduous trees that can provide shade and beauty and grow well in Washington County's clay soil include river birch, hackberry and varieties of red maple, Galloway said.
Hackberry is such a tolerant tree, it could grow in rocky, awful soil, Ipsan said.
Eberling said hackberry also grows well in any limestone-based soils in the valley, including in the Hagerstown area.
White oak, which is Maryland's state tree, and black walnut are two other varieties good for shade, he said. But many people object to black walnut trees because of the large nuts that fall off in autumn. White oaks drop acorns.
Flowers, fruit and beauty
Experts mentioned eight species of small, spring-flowering trees that have either fruit or seeds that birds like.
Galloway recommended crabapple, flowering dogwood, Washington hawthorn, pawpaw, serviceberry and redbud. Eberling also suggested staghorn sumac or smooth sumac.
For damp sites, plant river birch and sweet bay magnolia, Ipsan said. Sweet bay magnolia is typically associated more with sandy areas; Ipsan said she has seen it grow in our area.
Some trees do double duty. American holly doesn't provide great shelter from the wind, but birds like its berries, Ipsan said. Plus you can use holly prunings for decoration.
Norway spruce, with its droopy, hanging branches, also is decorative, Eberling said.
For more information about planting trees, check out these Web sites:
o Maryland Department of Natural Resources' Tree-Mendous program Web site has information about planting and caring for trees at www.dnr.maryland.gov/forests/treemendous/plantinginst.html.
o Marylanders Plant Trees' Web site ( www.trees.maryland.gov ) provides information about native species, planting trees and calculating the benefits of planting a particular tree variety in your area.
o Arbor Day Foundation's Web site ( www.arborday.org ) has information about tree care and planting the right tree in the right place.