A brilliantly Crayola-colored autumn came quickly this year. It's almost as if the rain washed the green from the leaves and turned them maroon, russet, orange and gold.
Beginning with the maroon dogwoods, I enjoyed watching the progression of colors -- orange sugar maples, scarlet red maples and, as I write this, brilliant yellow washes over the compound leaves of the bitternut hickories in our back yard.
I can't wait to see black gums and stewartias turn deep red. Many shrubs also add to the colorful mix. Witchhazel, fothergilla, oakleaf hydrangea, burning bush (Euonymus alatus), viburnum and spicebush are among those that add orange, red, russet and yellow to the tapestry that covers the landscape this month. Fall can be just as exciting in our own back yard as it can be in the mountains.
What is occurring is the slowing of photosynthesis, which causes trees to lose chlorophyll. This exposes other color pigments called carotenes (oranges) and xanthophylls (yellows) that were in the leaf all summer hidden under the green chlorophyll. Also, anthocyanins form. They are created in fall and account for the red in fall foliage. Tannic acid in some trees will cause leaves to brown and die instantly without spectacular color.
It may be interesting to know all of these technical aspects of fall coloration, but this has little to do with deciding what plants are showiest. That is done by looking at them, and it's not an exact science. Color is affected by annual variations in moisture and temperature. I'm exceptionally interested in the show made by this year's fall foliage in light of the severe summer drought.
Here is my personally researched leaf report for the region this autumn. Some leaves have begun to drop, but nothing that can't be mowed with the lawn. The majority will persist on the trees until cold, blustery weather blows in.
Most foliage is showing its autumn palette and, depending on the plant, is reaching or just passing peak performance. These are some of the showiest trees I have seen this fall:
* Sugar maples (Acer saccharum). These economically significant plants for maple syrup are equally as well known for fall foliage, especially in New England, where they dominate the woods. If you see a tall maple with brilliant yellowish, orange-red foliage, it is likely to be a sugar maple lighting up the neighborhood. Most of the ones I have seen are gorgeous and just starting to defoliate.
* Red maples (Acer rubrum). The ones that colored red this year were magnificent. Generally, you can only count on known hybrids that you get at garden centers for fall color, such as October glory and red sunset. Seed-grown red maples vary in leaf color and are seldom showy in fall. This year, though, many red maples have shown brilliant red. Even unknown species that haven't shown good color in years past are red this fall.
* Japanese maples (Acer palmatum). Many people like this tree for the numerous varieties that have red foliage throughout the entire growing season. The drawback of these hybrids is that they display no fall color. The leaves go from red to brown, but the species Japanese maples can be breathtaking in fall. These are the ones that have green leaves in summer and are turning brilliant, almost phosphorescent, pinkish purple to orange this year.
* Black gums (Nyssa sylvatica). You probably have noticed the low, rounded canopy on this tree, dotting the woods in fall, but didn't know you were looking at a black gum. This under-used native plant can commonly be seen in a natural setting such as Rock Creek Park. It's most noticeable in autumn because of its brilliant, evenly red color. I consider it to be one of the fullest and most outstanding trees in the woods. The perfect fall coloration is just an added attraction.
* Dawn redwoods (Metasequoia glyptostroboides) and baldcypresses(Taxodium distichum). Conifers aren't usually thought of as showy fall-coloring trees. Almost all are evergreen. Two do well in this climate and the needles are just starting to display their fall patina. The rust-colored foliage might not be showy on a common shade tree, such as an oak, but a deciduous conifer such as these specimens, displaying cones and russet red colored foliage in fall, is a standout.
* Hickories (Carya cordiformis). I like their striking golden yellow autumn leaves. In the couple of days it took to write this article, the hickories in our back yard have gone from green to brilliant yellow. They almost glow. In full fall color, they appear to have the sun shining on them, even when it's cloudy outside.
* Common dogwoods (Cornus florida). Although they must have moist, well-drained conditions, most dogwoods seemed to weather this drought well. Their foliage has shown its characteristic, dependable maroon color. You could pick out a dogwood on the forest floor or growing on the fringe of the woods simply by noticing the characteristic light maroon fall color.
* Sourwoods (Oxydendron arboreum): The main features of these trees are their summer flower and orange-red fall color. They leaf out after most other trees in this area, but it's worth the wait because the fall foliage was so showy. Many sourwoods dropped leaves too early to have their typical autumn impact. Those that remained colored beautifully and are especially outstanding as a background for the small fruits that formed on the drooping panicles left from this summer's flowers.
* Stewartia (Stewartia pseudocamellia): I name a stewartia with which I am familiar. This species is turning flaming red and will hold its foliage for several weeks in some sun and moist, well-drained soil. Their smooth bark is equally as handsome in tones of tan, red and gray mottling. There are other species of stewartia, Korean and native varieties. They generally color just as effectively, but I have not seen them this fall.
* Katsuratrees (Cercidiphyllum japonicum): This is one of my favorite shade trees. The fall color is an important selling point. Its foliage is turning pastel orange now. Even after the foliage browns and begins to fall, it exudes a spicy, almost chocolate smell, as leaves fall and crumble underfoot.
* White oaks (Quercus alba): I have been pleasantly surprised by these oaks the past several years, and it looks like they won't disappoint again this season. The outer edges of the leaves are beginning to show deep red. Although they will probably be the last trees to change for fall, they will be colorful well into November.
Check these plants yourself or install several and see what they do for you. Remember that micro-climate is the greatest contributing factor in how the plant performs. Your observations might be totally different from mine. A tree on one side of a garden might be bright orange, while the same species on the other side remains green. What's important is that you took the time to observe and considered fall colors as an integral part of your design.
Joel M. Lerner is president of Environmental Design in Capitol View Park, Md. His e-mail address is email@example.com; his Web page is at www.gardenlerner.com