Plant The Right Tree In The Right Place
Faced with a droopy, drab or dying tree that you recently paid big bucks for at the nursery? Chances are the tree is struggling in a site that is ill-suited for its health, says an expert in community forestry in Penn State's School of Forest Resources.
"Too many homeowners go down to the garden center and buy the first tree they see, or whatever is on sale," says Bill Elmendorf, instructor and urban and community forest program coordinator. "Homeowners should think in terms of how the tree will fit in the site and how it will look 10 to 20 years down the road."
Elmendorf says a little research into compatible tree species, local soils and municipal regulations can prevent major maintenance headaches or aesthetic disappointments. "If you choose the correct species for a particular site, the tree has less chance of dying and will mature to full growth faster," he says. "You also will save on maintenance over the life of the tree, as well as maintenance to sidewalks and curbs."
Elmendorf says understanding the planting site is the most important part of choosing a tree, especially to ensure a pleasing landscape. However, homeowners also should pay attention to what is below the ground, above the tree and near the site.
"You need to consider where storm drains, electric utilities and gas lines are," Elmendorf warns. "Pay attention to the location of traffic and business signs and how far away the tree will be from the curb or sidewalk."
Analyzing a site for planting a tree requires just a few basic steps.
Temperature. Know the temperature range for your area, particularly low temperatures. "Planting a tropical palm tree in Pennsylvania isn't a good idea," Elmendorf says.
"Most southern trees don't do well in northern climates. Tree species such as oak or poplar that normally thrive in northern states may not do well if they came from southern seed sources."
Moisture. Homeowners should estimate the amount of rainfall in their area. If the tree is to be planted in an urban setting, ask how much water is available. "Most city trees are surrounded by concrete and asphalt and don't get much moisture unless someone's washing off the sidewalk," Elmendorf says.
Soil. Most trees do well in neutral or slightly acidic soils. Trees such as red oaks, pin oaks and red maples planted in limestone-laden alkaline soils will experience nutrition problems. "This is a problem in urban areas because concrete is full of limestone, and asphalt roads usually are built on beds of crushed limestone," Elmendorf says.
Soil compaction. In cities and residential developments, soils are very compacted, making it difficult, if not impossible, for trees to thrive. "Almost all soils in urban areas are compacted and may be nutritionally poor," Elmendorf says. "I recommend digging a 4-by-4-foot hole to a depth of 4 feet and filling it with high quality topsoil."
Drainage. Elmendorf says a tree that gets too much water will be unhealthy. "Dig a hole and pour in a bucket of water," Elmendorf instructs. "If it doesn't recede an inch in an hour, you'll have problems."
Space. Elmendorf also recommends analyzing the growing space for trees, to make sure there is enough room for canopy and root growth. "Big trees need big space," he adds.
Homeowners also should be aware of how trees modify the climate of a home. To create shaded areas, Elmendorf recommends planting on the east and west side of a house. "Whatever you do, don't plant a tree on the southern side of the house," he says. "Trees on the south side prevent solar energy from reaching the house in winter."
Choosing a tree is a decision that should not be made in haste. Homeowners should take into account how tall the mature tree will be, what color its foliage turns in fall, and whether its crown is round, vase-shaped, spreading or upright. "Many trees produce fruit such as acorns or seed pods," Elmendorf points out. "Homeowners need to be aware that there might be a mess under the tree when fruit is produced. Some trees, such as the female ginkgo, bear fruit that produces a very unpleasant smell."
Elmendorf recommends consulting a reputable nursery or a qualified arborist before planting any trees. He also recommends the Penn State publication Street Tree Fact Sheets, available for $20 from Penn State's Agricultural Publication Distribution Center at (814) 865-6713.