Q: Can you suggest a good-looking small tree to plant in a large perennial bed in full sun? I want to create some shade so I can grow some of the shade perennials that I like. I thought I’d plant a couple of smallish trees close together to make a nice shady spot. — Norma Allen, Pikeville, Tenn.
A: There are almost too many good choices. Even if the list were limited to the very shortest trees and those that not only bloom in spring but also have good fall color, I could come up with a dozen or so that are hardy in your area. Plan a trip to your local botanical garden, and give them all a careful look. Keep in mind, however, that size is relative and subject to change. No tree stops getting bigger until it dies. The ones I cite here are said to top out at 30 feet or less, but eventually they’ll cast considerable shade. Of course, by then you may have decided you like your trees and shade perennials so much that you’ll let them all stay.
You’ve probably already considered the classic small trees: dogwood, crabapple, hawthorn, and the little magnolias. There are three kinds of dogwood to think about: native flowering (Cornus florida), Japanese (C. kousa), and hybrids. They bloom at different times, so you might want to plant one of each. Crabapples are lovely, but make sure to choose one that’s disease-resistant (‘Harvest Gold,’ ‘Professor Sprenger,’ Prairiefire’, and ‘Sugar Tyme’ are good). For hawthorns, the choice is simpler: Crataegus ‘Winter King’ is the most trouble-free. For very early blooms, you might consider Magnolia x loebneri ‘Merrill’ or ‘Ballerina,’ which are small but not as shrublike as their parent star magnolia.
Less common trees are well worth the hunt. The finely textured leaves and flowers of serviceberry (Amelan-chier spp.) make a delicate-looking tree in all seasons, but when it’s in full bloom or at the height of fall color, it’s quite striking. Either fringe tree (Chionanthus virginicus) or Japanese snowbell (Styrax japonicus), both of which bloom in late spring, will make a broad, spreading canopy. Summer bloom is hard to come by in trees, and that might give the last three on my list the ultimate edge. Sourwood (Oxydendrum arboreum) covers itself in unusual arching sprays of creamy blossoms in summer; by autumn its foliage turns fiery red. The large blossoms of Franklinia alata-maha and Stewartia pseudocamellia are similar to a single white camellia or rugosa rose; both have excellent fall color and peeling bark for a bit of interest in winter. Since a large specimen of any of these will be quite expensive, I would suggest that you plant a clump of three fairly close together (a good spacing rule is to double the height of the tree at planting), in an arrangement that casts shade strategically. As the trees grow, remove lower limbs or drooping branches. In 10 to 15 years, you may need to remove one or two of the trees, but a cluster planted now will provide shade more quickly.