Oxydendrum arboreum

Botanical Name: Oxydendrum arboreum
Common Name: Sourwood

Plant Hardiness: Zone 5

Flower: White flowers bloom in 10″ long drooping clusters. Quite showy in mid-summer

Bloom Time: Mid-July

Foliage: Large, glossy green leaves turn deep red in late summer

Fruit: Small, dry capsules clustered on flower raceme. Persists into winter. Showy against the fall foliage

Habit: A small tree or multi-stemmed shrub in New England. Upright growing as either form

Size: 20 to 30 feet tall in southern New England. Even taller in its native habitat further south

Sun Exposure: Full sun to partial shade

Native Habitat: Mid-Atlantic of United States and throughout the southern Appalachians.

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Description

Description: This deciduous tree is native to southeastern United States and is hardy in southern New England especially if planted in the landscape as a reasonably good sized tree or shrub. As a tree in its native habitat, it will grow to a height of 50 feet or so; however, here in New England, a 30 foot specimen would be a large one. Its leaves are large, not unlike those of a peach tree. They turn a rich burgundy red in late summer, holding this color throughout late summer and early fall. The flowers are formed in droopy clusters or racemes, 8 to 10 inches long, and are very beautiful in mid-summer. They are quite similar to those of Pieris floribunda. Even after the flowers have fallen, the seed pods remain a light cream color and provide a beautiful contrast to the autumn colored foliage. In New England when the trees are young and vigorous, the new growth will suffer some die-back through the winter. Often this will destroy the leader of a plant, turning it into a shrub form; but as a shrub form or multiple-stem small tree, it is also an excellent plant. Oxydendrum is a member of the ericaceae family; and therefore, like rhododendrons and azaleas needs a peaty soil and requires plenty of moisture although good drainage is also essential. I’ve never seen it grown this way, but I understand it is very effective trained into a broad pyramidal tree with branches horizontal to the ground all the way down to the base. This is a tree that can be planted quite close to a house if the situation warrants as its root structure is not coarse enough to cause damage to masonry, and its branching is such that it can be kept in control. In the New England area the overall size of the tree will never become too large although one planted at the southwest corner of our house is over 20 feet tall and is still growing.

Tom Dilatush gave us a few seedlings several years ago from the coldest area he has seen Oxydendrum growing. I believe this was somewhere on a mountain in Pennsylvania. The Oxydendrum we grow now are seedlings from that plant and should be very hardy. This tree is so spectacular it should be used far more than it is today.