Sand Post Oak

Size, growth and what to expect

A tree of deep coastal-plain sands, sand post oak grows slowly, about a foot a year in its youth on an average site by our growth estimator's model. It is a slow-growing, sometimes scrubby tree. It generally reaches 30 to 40 feet with a dense rounded crown, and it can stay a shrub. Individual trees have reached 234 years.

The first acorns take 20 to 30 years, and in post oak proper, of which this is often treated as a variety, good crops come every 2 to 3 years. It flowers from March to May. The acorns run about a half inch to an inch long and ripen from September to November, and turkeys and other game birds, songbirds and small mammals eat them. The leaves feed the caterpillars of the imperial moth and the banded and Edward's hairstreaks. Dwarf post oak, its other name, describes its smaller stature.

It grows wild on deep sand and gravel from southeastern Virginia west to Missouri and eastern Oklahoma, south to central Texas and east to central Florida, on sandhill ridges and in scrub.

How to grow Sand Post Oak

Sand post oak is for the hot, dry, sandy spot where lawn trees fail: a south-facing bank or deep sand. Full sun, no irrigation once established. It stays small, so 15 feet from a building is enough.

Plant a dormant sapling, bare-root or potted, between leaf fall and bud break, in a hole twice the root width and no deeper. Set the flare at ground level and backfill with the same sand you dug. Compost holds water this oak does not want. White oak acorns sprout on contact with damp ground, so sow them on arrival, an inch deep, under hardware cloth against mice.

Water deeply every two weeks the first summer, then stop; overwatering kills it faster than drought. Mulch lightly with pine straw, off the trunk. Deer browse and rabbits gnaw it, so tube or cage it until the leader is above browse height, about four years on a slow tree. Stake only if it leans.

Like other oaks, sand post oak is wind pollinated and needs pollen from another tree to set acorns, so plant two or more seedlings. The taproot goes down fast, so plant it young and never move it. Growth is slow and acorns are many years off. Oak wilt troubles red oaks far more than white oaks. Keep fill, traffic and lawn sprinklers off its roots.