Photo: Eric Hunt, CC BY-SA 4.0 · Wikimedia Commons

Arkansas Oak

Quercus arkansana

Also called Arkansas water oak, Quercus caput-rivuli.

A rare red oak of the Gulf Coastal Plain, a slender tree with broad, round-tipped leaves, and one that Florida lists as threatened.

RareWildlife valueDrought tolerant

Type: Medium tree
Mature height: 20–60 ft
USDA zones: 5–9
Growth rate: Medium
Sun: Full, Part
Soil moisture: Dry, Average
Grows wild in: Sandy barrens, rich moist slopes and the forest understory
Native range: 7 states, north to Arkansas, south to Florida and west to Texas
List all 7
Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi and Texas
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Arkansas oak is a red oak that Charles Sargent described in 1911 from trees near Fulton, in southwest Arkansas. It is a relict, once spread across the Coastal Plain and now left in scattered stands. The IUCN Red List rates it vulnerable, NatureServe ranks it vulnerable, and Florida lists it as a threatened plant. Pine plantations, logging, drought and feral hogs press on the wild stands, and young trees are scarce in them. Plant it on a sandy slope at the edge of pine woods, or as a slim shade tree where a broad oak would crowd a small lot.

Size, growth and what to expect

A tree planted in 1983 at the Hillier Gardens in England stood 17.7 meters, about 58 feet, in 2023. That is close to a foot and a half a year, the pace our growth estimator gives a medium grower. Expect 20 to 60 feet, with a narrow crown. A tree planted in France in 2004 bore its first acorns in 2021.

It flowers in spring. The acorns take two seasons to ripen, as in every red oak, and are ready in the fall of the second year. They are small and nearly round, three eighths to five eighths of an inch, in a thin, shallow cup. Squirrels, raccoons and deer eat them.

It grows wild on the Gulf Coastal Plain from southwest Georgia and the Florida Panhandle to east Texas, most common in southwest Arkansas. Some 2,500 to 10,000 wild trees are known, and 132 of the known stands lie on Eglin Air Force Base in Florida.

How to grow Arkansas Oak

Arkansas oak wants full sun or light shade and a deep, well-drained sand or sandy loam on the acid side. In the wild it grows beneath pines on sandy slopes above the heads of small streams, so light shade suits it. Once rooted it rides out long dry spells, but keep it off wet ground and out of salt spray. Set trees 25 feet apart, and keep each one 20 feet from a wall and more than 50 feet from overhead wires.

Saplings ship bare-root or potted. Plant them dormant, from leaf fall until bud swell, in a hole wider than the roots and deep enough for the taproot. 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 an inch deep under hardware cloth. For spring, hold them damp in the refrigerator for four to twelve weeks first.

Water every week or two through the first summer, then only in a long drought. Deer browse young oaks, so guard each sapling with a tube or cage for its first three years. Keep the mulch thin at the trunk so voles do not nest there. Little pruning is needed beyond keeping one leader while the tree is young.

The flowers are wind pollinated, and an acorn crop wants another oak nearby. As a red oak it can catch oak wilt where that disease occurs, so prune only in the dormant season, to avoid the beetles that spread it. In the wild it crosses with bluejack and water oaks.

Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them.

Sources (13)