Chestnut Oak

Size, growth and what to expect

Chestnut oak grows slowly, about a foot a year in our growth estimator. Expect 50 to 70 feet with an equal spread. Forest trees reach 65 to 80 feet, and rarely 100.

It flowers in April and May as the leaves open, and the acorns ripen in a single season, dropping from early September to early October. That is weeks ahead of most upland oaks. Trees bear from about 20 years, though sprouts from a cut stump have borne at 3, and heavy crops come only every 4 or 5 years. The acorns are large, up to an inch and a quarter long, in a thin, warty cup, and they are sweet. Deer, turkeys, grouse, squirrels, chipmunks and mice eat them.

It grows wild from southwestern Maine and southern Ontario west to southeastern Michigan and southern Illinois, and south along the Appalachians to Georgia, Alabama and northeastern Mississippi. It reaches from near sea level on the New Jersey coastal plain to about 4,600 feet in the southern mountains.

How to grow Chestnut Oak

Chestnut oak wants full sun or light shade and a well-drained soil, and it does well on poor, dry, sandy or rocky ground. It prefers acid soil but stands some lime, and once rooted it takes drought. It will not take soil that stays wet. Set trees 50 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. The deep taproot makes it hard to move once grown, so plant it young and plant it once. 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. Chestnut oak acorns sprout soon after they fall. Sow them on arrival, an inch deep, under hardware cloth. An inch of leaves over the bed helps them root, but a thicker layer makes weak, pale seedlings.

Water every week or two through the first summer, then only in a long drought. Deer and rabbits browse young oaks, so guard each sapling with a tube or cage for its first three years. Keep one leader while the tree is young, and prune only in the dormant season.

The flowers are wind pollinated, and an acorn crop wants another oak nearby. Chestnut oak belongs to the white oak group, so its acorns ripen in one season and sprout as soon as they fall. Oak wilt can infect it. A white oak usually loses a limb at a time rather than dying within weeks, but prune in the dormant season all the same, to keep away the beetles that carry it. It is one of the two oaks, with white oak, that spongy moth caterpillars favor most, and cankerworms and tent caterpillars feed on it too. Ambrosia beetles bore into trees weakened by drought or fire.