Tall Shade Trees

Elisabeth — Tue, 03 Mar 2009 13:10:00 GMT

The other day, the mayor of my small town suggested that we start a shade tree commission. He was concerned that many of our dependable street trees are reaching the ends of their natural lifespans and will need replacement in the next ten years. Our town has always been proud of its tree-lined streets and we want to continue that ecologically and horticulturally sound tradition.

The problem is, which trees should our new commission choose? The old trees are mostly oaks and maples, the fondly-remembered elms long since destroyed by Dutch Elm Disease. To keep our leafy canopy, we need old-fashioned, tall hardwood trees that will last a long time. I am sure that we will install additional oaks and maples, but in the interests of biodiversity, we need some other choices. I suggested two: the American sycamore (Planus occidentalis) and my favorite, the tulip poplar (Liriodendron tulipifera).

The sycamore grows at a moderate rate and has green leaves that might remind you of large maple leaves. A mature tree can be 70-100 feet tall, providing lots of welcome shade in the summer. For me, the most interesting thing about the sycamore is that its bark exfoliates or peels off, giving the trunk a mottled, almost camouflage-like appearance (see below). This provides a bit of winter interest. Sycamores have a reputation for toughness and make good street trees--even in high traffic areas.

The tulip tree or tulip poplar grows tall and straight and reaches 60-100 feet in height. The spring flowers are exotic-looking and beautiful, with goblet shaped chartreuse and white blossoms accented with orange (see below). The leaves, which turn from green to yellow in the fall, are shaped like the stylized tulips you might see on old-fashioned quilts. George Washington planted tulip trees and Mount Vernon and Jefferson sent seeds to friends in England and France. Tulip trees, being native to our country, are even more American than that famous import--apple pie.

Birches

Elisabeth — Fri, 17 Oct 2008 12:00:00 GMT

Birches or betula are the stuff of poetry and history, and have long been associatied with beauty, grace and a bit of mystery.. Robert Frost's long poem, "Birches", celebrates the trees, associating them with youth. School children study the traditional birch bark canoes that Native Americans in the eastern United States built to navigate rivers and streams.

The most common birch in my part of the world is the paper birch or Betula papyrifera. It is short-lived--at least compared to maples or oaks--with white, peeling bark and oval-shaped leaves. It is a great tree anywhere, but especially in suburban yards, where I often see several grouped together. The trees are lovely during the growing season, but come into their own after the leaves are gone, when the white trunks really shine.

Birches can be wonderful understory trees, planted near the edges of wooded areas. They are also great garden subjects that are especially effective when underplanted with specimens that have either purple flowers or leaves. If you live in a frost-free area, try underplanting birches with strobilanthes or Persian shield. If your climate is colder, try seasonal installations of purple-flowered impatiens or, possibly, Japanese painted fern.

Growing Wise : exfoliating bark

Tall Shade Trees

Birches