Swamp White Oak

Size, growth and what to expect

Swamp white oak grows at a medium pace, about a foot and a half a year in our growth estimator. Expect 50 to 60 feet with an equal spread, an open, irregular crown and low limbs. Forest trees reach 60 to 75 feet, rarely 100, and many live 300 years or more.

It flowers from April to June as the leaves open, and the acorns ripen the same year, falling in September and October. Trees bear from about 20 years, with good crops every 3 to 5 years. Each acorn is three quarters of an inch to an inch and a quarter long, half or more inside its cup. They are sweet, and squirrels, deer, black bears and wood ducks eat them. In one Wisconsin study they made up 27 percent of what wild ducks ate. People can eat them too, once the bitterness is leached out.

It grows wild from southwestern Maine and southern Quebec west to southeastern Minnesota, and south to Missouri, Kentucky and Virginia. It is most common and grows largest in western New York and northern Ohio.

How to grow Swamp White Oak

Swamp white oak wants full sun and a moist, acid soil. It takes heavy clay, poor drainage and spring flooding better than most oaks, but not water that stands all year. Once rooted it also rides out a dry summer. In alkaline soil its leaves turn yellow, so keep it to ground on the acid side. Set trees 50 feet apart, and keep each one 30 feet from a wall and more than 50 feet from overhead wires.

Saplings ship bare-root or potted. Plant from leaf fall until bud swell, in a hole wider than the roots and no deeper. Set the root flare at the soil line, put the native soil back in, and keep the mulch clear of the trunk. Swamp white oak acorns sprout soon after they fall and do not store. Sow them on arrival, an inch deep, under hardware cloth.

Water every week or two through the first two summers, since young trees can be slow to settle. Deer and rabbits browse young oaks, so guard each sapling with a tube or cage for its first three years. Open-grown trees keep their low limbs, so raise the crown a little at a time where you need clearance, and prune only in the dormant season.

The flowers are wind pollinated, and an acorn crop wants another oak nearby. As a white oak, it ripens its acorns in one season, and they root before winter. It is highly susceptible to oak wilt, so keep to dormant-season pruning, since spring cuts draw the beetles that carry the fungus. Oak anthracnose can damage a tree but is seldom fatal. Insects infest many of the acorns.