Multi-season appeal for your landscape
Gorgeous in both summer and fall, the sourwood tree might be the perfect addition to your landscape. Considered both a shade tree and an ornamental tree, it can add visual interest and beauty to your garden with its bell-shaped, fragrant blooms in summer and its brilliant leaves in the fall.
The sourwood tree (Oxydendrum arboreum), also called sorrel tree by some, is a medium-sized native tree with a mature height of 25-50’ and a spread of about 20’ which, once it is established, grows extremely well in our region. According to the Missouri Botanical Garden, it is a “beautiful small specimen flowering tree with multi-season interest for lawns, patios, shade gardens or open woodland areas.” This ideal understory tree is frequently found in wooded, sloped areas and is frequently seen growing with azaleas and rhododendrons.
Flowers that resemble lilies of the valley dangle from the branches and usually appear during early summer (June and July). The white blooms provide passersby with a delightful fragrance; bees happen to love the blooms too. According to the Arbor Day Foundation: “For honey lovers, the sourwood offers an additional bonus. Honey produced from the flowers of this tree is considered by many to be unmatched by clover, orange blossom, fireweed, or any other honey.”
The leaves are a shiny green and may remind onlookers of a peach tree leaf, or even a serviceberry leaf. If you were to taste the leaf, it would fill your mouth with a sour taste, which is why its common name is sourwood. In the fall, according to the Arbor Day Foundation, “the leaves turn intensely beautiful shades of brilliant crimson, purplish-red and sometimes yellow.” The bark on a mature sourwood tree is often scaly and features a grayish color. Older bark may appeared cracked (or fissured), but is appealing to the eye.
This lovely, deer-resistant tree will grow in part shade to full sun and requires low maintenance once it is established. It requires low amounts of water, so once it has established itself in its location (i.e. after you plant it and it has rooted in place), it will need minimum care. However, according to the Virginia Cooperative Extension at Virginia Tech, the sourwood tree can be difficult to start in your garden: “Despite its grace and beauty, sourwood trees are notorious for being difficult to establish in landscapes. If you plant ten trees, four or five will die and half of the survivors will be unthrifty. Why such a poor transplant survival rate? Part of the issue is related to exacting cultural requirements. Sourwoods require a well-drained acid soil.” Planting container-grown seedlings can increase success rates. Another consideration for gardeners from VCE: “sourwood plants are noted as being sensitive to air pollution, thus this species may not be suited to urban environments.” There are no serious disease or insect issues. Sometimes twig blight and leaf spot may appear, so be on the look-out for those problems. ❖
Missouri Botanical Garden’s website provides valuable information on Oxydendrum arboreum.
Common Name: Sourwood
Type: Tree Family: Ericaceae
Native Range: Eastern and southeastern United States
Zone: 5 to 9
Height: 20.00 to 50.00 feet
Spread: 10.00 to 25.00 feet
Bloom Time: June to July Bloom
Sun: Full sun to part shade
Suggested Use: Flowering Tree
Flower: Showy, Fragrant
Leaf: Good fall color