Quercus marilandica

Common Names

Blackjack Oak, Jack Oak, Black Oak, Barren Oak

Summary

Blackjack Oak is a small to medium deciduous oak native to the central and eastern United States, typically grows 20–40 ft tall with a compact, sometimes scruffy form on poor dry sites, and a trunk that is nearly black with irregular furrows; leaves are obovate with 3–5 shallow lobes, dark green and glossy above with a lighter, pubescent underside; flowers are catkins in spring and acorns ripen in autumn of the second year; the tree tolerates drought and poor soils, prefers dry, well-drained substrates, and is fire-tolerant with vigorous resprouting after fire, often forming colonies in savannas and barren woods; wildlife benefits include acorns used as food and habitat provided by the tree; wood is heavy and dense and used for fuel and charcoal. Cultivation focuses on full sun and well-drained acidic soils; drought tolerance is notable, while wet soils are avoided. Propagation is by seed: acorns should be collected from healthy trees and sown soon after ripening, or stratified in damp sphagnum peat moss for three to four months at cold temperatures (36–40°F); seeds should not dry out and transplant success improves with fresh stock. Pruning is best done during the dormant season, removing only dead or unhealthy branches and not removing more than one-fourth of foliage at a time. In landscape use, blackjack oak is more commonly found in naturalized or woodland settings due to its slow growth and dry-site preferences, and its value for wildlife and as a fire-resilient, drought-tolerant specimen makes it suitable for native plantings and habitat-focused landscapes.

Lifecycle

Perennial

Height

360-600 inches

Spread

20-40 feet

Hardiness Zones

Zones 6-9

Sunlight Requirements

Ideally full Sun. Tolerates partial sun and partial shade.

Soil Type

Dry, well-drained, acidic soil (often sandy or loamy).

Soil Drainage

Dry, well-drained soils

Soil pH

5-8, Tolerates a wide range: mildly acidic, neutral, and mildly alkaline soils

Bloom Color

Insignificant

Bloom Time

Spring (March to May)

Foliage Color

Dark green

Fall Foliage Color

Yellowish-brown to russet, dull reddish-brown, red to brown

Leaf Lifecycle

Deciduous

Growth Rate

Slow, about 1.7–4.4 inches per year (seedlings to sprouts) in Missouri

Seasons of Interest

Spring, Fall, and Winter

Propagation Methods

Seeds, Cuttings

Attracts Wildlife

Attracts birds and butterflies