Trees for Organic Gardens

Native trees can cope with native pests, survive in extremes, and have interesting color.

By Guy Sternberg

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MAPLES (Acer)
Features: The brilliant autumn color of our native sugar maple is the gold standard by which all other fall foliage is measured. Luckily, this snow-loving species shares its best attributes with maples in warmer, drier climates. In fact, native maples have adapted to nearly every soil type and watering requirement in North America. For example, the canyon maple in the southwest tolerates dry soil and, along with the more cold-hardy black maple, high pH.

Choices: Maples are naturally found in the Deep South (Florida maple), the southeastern mountains (chalk maple), and exposed midwestern sites (black maple). When you add in our other maple species, these trees comprise one of the most diverse and colorful of all tree genera, with more than 100 species thriving throughout most of the northern hemisphere. Every yard should have at least one native maple.

BIRCHES (Betula)
Features: For many people, the appeal of a birch tree lies in its glowing white bark. Our native birch species have bark that ranges in color from white to rosy brown to a shiny steel gray and exfoliates from the trunk in strips and swirls. Native birches are much better adapted to North America's more stressful climates than imports. A birch under stress, especially from heat or drought, invites a beetle that bores into the wood and eventually kills the tree. And this is particularly a problem for the nonnative birches, which haven't evolved to cope with this insect.
Uses: All birches tolerate wet soils, and most prefer them. The paper birch is among the most winter-hardy of all deciduous trees. Although not especially long-lived as trees go, with adequate moisture and sunlight, and freedom from weed competition, birches can grow very rapidly into highly ornamental shade trees that live for 30 to 40 years.

SUMACS (Rhus)
Features: Sumacs suffer from a bad reputation. Most sumac species clump from their roots, forming thickets that many people perceive as being weedy. This tendency is an adaptation to their natural environment, where they must compete for a space in the sun following fires or other calamities. (This is an advantage, however, if you want a dramatic grouping of a single species.) Worse, many people cannot say sumac without the preface poison (referring to the sap reaction, phytodermatitis, that many people have), yet we have only one toxic species, albeit a very colorful one, and you are unlikely ever to see it unless you wade into its swampy natural habitat. Sumacs are small, often shrubby, and therefore capable of embellishing the tiniest backyards with the most brilliant fall color imaginable.

Uses: Their winter form is artistic, and their flowers and fruits can be striking and long-lasting. Sumacs bring nothing but pleasure in the home garden and are among the easiest of all small trees to grow.

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