Blackjack Oak (Quercus marilandica)

Blackjack Oak (Quercus marilandica)

This tree in the red oak group is referred to as a "scrub oak" by some referring to the smaller stature that can be an asset in the urban environment. Blackjack as a common name refers to the oblong or wedge shaped leaf that is variably three lobed and widest near the tip of the leaf. The leaf is deep green and glossy on top and rusty pubescent beneath. The foliage is quite drought resistant. Fall color is russet and not showy. The tree tolerates some notably poor soils.

This tree is a common pioneer invader in Virginia. Flood plain species and pioneer invaders have proven to be some of the most urban tolerant trees we use. In Ohio, blackjack oak is rare but occurs in the unglaciated area of the state in southern areas of zone 5 and in zone 6. The fact that it occurs on unglaciated areas suggests that it may prefer more acid soils, however, data on this is lacking. It is likely to be found in an old field especially if the area is dry and impoverished. The twiggy growth and dwarf habit makes the blackjack oak a poor timber tree but offers advantages in the restricted space found in our cities. It typically occurs in zones 6 and higher, but will grow well into zone 5. There are significant populations in southern Michigan which could provide a more cold-hardy seed source if needed.