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Sourwood

Oxydendrum arboreum

Common names:
sourwood, sorrel tree, lily-of-the-valley tree

Content Detail

Sourwood is an attractive tree with white flowers that bloom in early summer and excellent fall color. It can be difficult to grow in northern Illinois because it requires acidic soil.

  • Family (English) Heath
  • Family (botanic) Ericaceae
  • Tree or plant type Tree
  • Foliage Deciduous (seasonally loses leaves)
  • Native locale North America
  • Size range Medium tree (25-40 feet)
  • Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8
  • Soil preference Acid soil, Moist, well-drained soil
  • Tolerances Wet sites
  • Season of interest early summer, midsummer, early fall, mid fall
  • Flower color and fragrance Fragrant, White
  • Shape or form Oval, Pyramidal
  • Growth rate Slow

Size and form:

Sourwood is a pyramidal to oval tree that grows 25 to 30 feet high and 20 to 25 feet wide.

Native geographic location and habitat:

It is native primarily to the southeastern United States and commonly found on well-drained upland slopes.

Bark color and texture:

Bark is gray-brown and deeply ridged with the ridges often divided into a somewhat square pattern.

Leaf or needle arrangement, size, shape, and texture:

It has simple, alternate, 3 to 8 inch, elongated leaves with finely toothed edges. The leaves are dark green in summer and change to red or a mix of red and orange in fall.

Flower arrangement, shape, and size:

This tree produces fragrant, white sprays of flowers in early summer. Their shape is reminiscent of lily-of-the-valley.

Fruit, cone, nut, and seed descriptions:

It produces small, persistent, tan, dry capsules.

Plant care:

Sourwood requires an acidic soil that is moist and well-drained. It prefers full sun to part shade.

List of pests, diseases and tolerances:

There aren’t any serious insect or disease problems.

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