Southern Red Oak

Size, growth and what to expect

It grows at a medium pace, moderately fast for an oak, about a foot and a half a year in our growth estimator. Expect 60 to 80 feet with a crown 60 to 70 feet wide. It lives to about 150 years.

It flowers in April and May, and the acorns ripen in September and October of their second season. Seed production begins at about 25 years and peaks between 50 and 75, with good crops every year or two. The acorns are about half an inch long, much smaller than a black oak's, and squirrels and blue jays scatter them. Its leaves feed the caterpillars of the banded and white M hairstreaks.

It grows wild from Long Island and New Jersey to north Florida and west to the Brazos River in Texas. It usually grows on dry ridgetops and upper slopes, and in the South Atlantic states mostly in the Piedmont.

How to grow Southern Red Oak

Southern red oak wants full sun or part shade. It grows in a well-drained, acid soil, from sandy loam to gravel or clay loam. It takes drought and poor, worn soil, and it tolerates brief flooding. At the northern edge of its hardiness, as in St. Louis, give it a sheltered spot. Set trees 60 feet apart, and keep each one 35 feet from a wall and more than 50 feet from overhead wires.

Saplings ship bare-root or potted. Plant dormant saplings 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. Red oak acorns need a winter before they sprout. Sow them in fall half an inch deep under hardware cloth. For spring, hold them damp in the refrigerator for 30 to 90 days first. A mulch of leaves or straw under the cloth protects a fall bed.

Water every week or two through the first summer, then only in a long drought. Deer browse it only moderately, but a tube or cage for the first three years keeps deer and rabbits off a young sapling. Once it is grown, keep trenching, grading and heavy traffic off its roots, since root damage during building can kill it.

The flowers are wind pollinated, and an acorn crop wants another oak nearby. As a red oak it is highly susceptible to oak wilt, though the disease is virtually unknown south of the 35th parallel. Prune only in the dormant season all the same, to avoid the beetles that spread it. Its thin bark scars easily in fire, and heart rots follow the wounds. Fall cankerworms strip the leaves in some years.