Garden Column for Successful Gardener
Darrell Blackwelder
August 5, 2003

    Few native trees have the potential as a landscape ornamental as the sourwood (Oxydendrum arboretum). Panicles of lily-of-the-valley type flowers followed by brilliant scarlet color in early fall make this tree a highly, desirable landscape specimen.
    Sourwood, also known as sorrel-tree or lily-of-the-valley-tree, is best known as an important source of honey for beekeepers. It is considered a small, undergrowth tree that grows throughout the Piedmont uplands and along Piedmont streams on well-drained lowland areas. The showy tree is commonly seen along highways and edges of hardwood forests along the highways of Piedmont and the mountains of North Carolina.
    Sourwood is among the latest of the trees to bloom, with white, bell-shaped perfect flowers appearing from late June to August. The dense flower clusters resemble Japanese pieris(pieris japonica), except the panicles of the sourwood longer and more open. Maintaining this beautiful bloom in the fall against scarlet leaves make it a spectacular landscape plant.
    Planted in dense shade the tree develops a slender trunk and small crown however, placed in the open landscape it forms a short, often leaning trunk dividing into several stout, ascending limbs becoming ornate. As the tree matures the bark becomes dense and corky; another design attribute.
Insects do attack sour wood but normally do no serious harm. There are no serious diseases that affect the growth and development of sourwood.
    These trees prefer well-drained slightly acid soils. Avoid over liming areas around the tree. Sourwoods thrive in both moderate shade and full sun; however, placement in full sunlight is best for ample flowers.
    Growth of the tree is somewhat slow and the tree is extremely difficult, almost impossible to transplant from the wild. Your best bet is to locate a nursery that has them in containers. Sourwoods are native trees and may be difficult to locate, but the extra effort will be worth it.