Plant library · Ornamental & Flowering Trees
Oxydendrum arboreum
Sourwood is a native shade tree that brings white, lily-of-the-valley-like flowers in mid to late summer and brilliant red fall color to the garden plan. At about 30 feet tall and 20 feet wide, it works best as a small-scale canopy tree rather than a tight bed planting. Its pollinator-friendly bloom makes it especially useful where a flowering tree can anchor a native planting area.
Give sourwood a visible position where its summer flowers and autumn canopy can be appreciated from a patio, window, or regularly used path. It can serve as a specimen or as part of an open woodland composition, but leave the trunk zone outside the active footprint of paving, play areas, and dense shrub borders. Allow room beneath and beside the canopy for lower plantings without forcing them into a narrow maintenance strip.[1][2]
Space sourwoods 20 feet apart, center to center. That distance matches the tree's mature 20-foot width, so neighboring canopies may meet over time; use a wider interval where you want a clear gap for views, air movement, or access between trees. Reserve a roughly 10-foot radius from the trunk for the mature canopy, and avoid placing structures or paths where later branch spread would create a pinch point.
Place sourwood in full sun with moderate, steady moisture rather than in a dry, exposed pocket. It is suited to acidic, moist but well-drained soil, so plan it away from places that stay waterlogged after rain. A soil zone shared with other plants that accept acidic conditions will simplify bed design and irrigation choices.[1][2]
The tree carries its white flower clusters in summer, then shifts to a strong red fall display. Site it where this late-season color can read against evergreen foliage, a darker backdrop, or open lawn rather than disappear into a crowded mixed border. As a deciduous tree, it opens the area to more light after leaf drop, changing the winter character of the bed below.[1][2]
Avoid treating sourwood as a transplantable filler tree. Establish it in its intended position while young, and favor a sheltered garden setting over a heavily urban, pollution-exposed site. Its need for acidic, well-drained soil is a defining placement constraint, so do not use it to bridge between incompatible soil zones.[1][2]
Editorial content updated 2026-07-20.