Sourwood

Size, growth and what to expect

A sourwood seedling flowers 4 to 5 years after sowing. Growth is slow, about a foot a year in its youth on an average site by our growth estimator's model, and it stays slow in established stands. Around a house count on 25 to 50 feet with a trunk 8 to 12 inches through, and the record forest tree is 80 feet. In the forest it usually stays in the understory all its life. Trees typically live about 100 years, and one has been ring-counted to 263.

The white bell flowers hang in drooping sprays 4 to 8 inches long from late June into August, and bees make a rich, sought-after honey from the nectar. The capsules, a quarter to a half inch long, ripen in September and October and shed tiny seed all winter. Sorrel tree, its other name, comes from the sour taste of the leaves.

It grows wild from southwest Pennsylvania, southern Ohio and Indiana south to Louisiana and northwest Florida, and east to the Atlantic coast from southern Virginia to central North Carolina, up to about 5,000 feet.

How to grow Sourwood

Sourwood needs acid soil that drains, in full sun or light shade; sun gives the most bloom and the best color. Keep it out of lawn strips and salted roadsides. It grows slim, half as wide as it is tall, so 12 feet from the house is enough. Set trees 12 feet apart.

Saplings ship bare-root or potted. Plant a sapling while dormant, in a hole twice the root width and no deeper, flare at grade, native soil only; if your soil is not naturally acid, choose another tree. Mulch with pine straw, off the trunk; no stake. Seed is dust-fine and needs light: sow it on the surface of moist acid mix in spring, uncovered, and keep it misted under a screen.

Young sourwood dries out easily, so water weekly through the first two summers. Deer and rabbits can both damage a young sourwood, so tube it until the trunk is above browse height, about four years. It shapes itself; prune only broken limbs.

Each flower carries both male and female parts and insects pollinate it, so there are no male and female trees to pair. Growth is slow and a transplanted sourwood may sit a season before it moves. Yellow leaves with green veins mean the soil is too sweet. Flowers come in midsummer on new growth, and leaves start turning in September.