Looking for a small- to medium sized-tree that flowers in early summer, retains its attractive flower stalks until early fall, and then develops brilliant fall color? The sourwood (Oxydendrum arboreum) fits the bill and can find a place in almost any landscape.
photo JC Raulston Arboretum
Sometimes known as Sorrel Tree or Lily-of-the-Valley Tree, sourwood is the single member of the Heath family, which includes azaleas and rhododendrons, achieving tree stature in our area. Its small, cream-colored flowers appear on gracefully drooping racemes in early summer, attracting bees and yielding the distinctive sourwood honey.
Individual flowers are small, but thousands will cover a tree with a veil of white. Even as the flowers fade, their yellowish stalks and fruits remain ornamental for several weeks. Sourwood leaves are three inches to eight inches, elongated and somewhat glossy. A rich green in summer, in fall they turn varying shades of red, purple and yellow, often on the same tree. Even the bark on mature sourwoods is ornamental, a warm brownish gray, divided into deep, blocky furrows.
Sourwoods grown in the open will assume an irregular pyramidal shape, with branches that are held horizontally to somewhat drooping. You may have to do a bit of pruning at the base to keep a sourwood to a single trunk, but even then you shouldn’t expect a perfectly symmetrical tree. When you see them in the woods, they almost always seem to lean considerably as they age. They rarely become really large trees. They might reach 30 or 40 feet in height in the wild, with a trunk a foot in diameter, but most garden trees are smaller. In cultivation, they will reach fifteen feet in about as many years. Luckily for us gardeners, they will flower at three to four years of age.
Native sourwoods are found either in the forest or colonizing in open fields, so they can take either full sun or shade; flowering and fall color will be better with greater light. If you don’t want to give yours specimen status in the middle of a lawn, planting it at the edge of the woods would be a good solution. Sourwoods occur from well-drained bottomlands to dry hillsides, so are not too fussy about moisture once established. Like most members of the Heath family, they do want acid soils.
Sourwoods may not be at every garden center but are definitely available at area specialty nurseries and are worth seeking out. Both you and the bees will enjoy one in your landscape.
Featured image – Sourwood / JC Raulston Arboretum
Charlie Kidder gardens in Cary, where he tries to cram every plant possible into his half acre. He also helps to care for the xeric gardens at the JC Raulston Arboretum. He can be contacted at firstname.lastname@example.org.