Ask The Tree Doctor - Letters

American Forests, Autumn, 2000

Don't know when to prune? Curious about lobed leaves? Have no fear--the Tree Doctor is here.

Q: I heard that maples absorb carbon dioxide. Do you know if oaks and pines do too?

Joan Smith, via e-mail

A: All trees absorb [CO.sub.2] and break down into carbon and oxygen. They store the carbon in the wood as they grow and emit the oxygen. The better suited a tree is to the climate and site conditions, the better job it will do sequestering carbon. For more information, see AMERICAN FORESTS' Building Greener Neighborhoods.

Q: Our local power company has taken to devastating trees like never before. How do we stop them? They cut below the lines.

Anonymous, via e-mail

A: Many communities face this problem. The job of power companies is to provide power, and when trees grow into power lines they need to be cleared. The enlightened company can prune selectively, thinning instead of topping trees. Sometimes it is a matter of meeting with the powers-that-be and working out a long-term maintenance program, including a removal and replacement program for trees too big to be beneath power lines. Check out the more progressive programs in Sacramento and San Jose, California. The International Society of Arboriculture has established standards for tree pruning at www.ag.uiuc.edu/[sim]isa/welcome.html. You also could consult the nonprofit group Plant Amnesty at www.plantamnesty.org.

Q: I planted a Maple Autumn Blaze at my Dad's on Father's Day. It was about 10 feet tall. How much should we be watering it? The tog only said semi-moist.

Linda Coulter, via e-mail

A: All new trees need about 15 gallons of water each week until they are established. Without rain, that would be equivalent to laying a garden hose in the basin of the tree and running it on very low pressure, almost a trickle, for 15 to 20 minutes. You should adjust according to your weekly rainfall. We suggest doing this until the late fall rains and snow. Then check it next year. Probe into the soil 3 to 4 inches to see whether it is dry. Water as needed, especially when you don't have rain. There is no need to provide extra water in the winter in cold climates, when the tree is dormant.