Bur Oak Seedling

The bur oak is the largest of the North American oaks. It regularly reaches 100’ in height, with a trunk diameter of up to 10’.  

With an exceptionally long tap root, the bur oak can withstand drought by searching out underground water that’s deep below the surface. It’s a survivor and can withstand urban pollution, a huge range of soil pH levels, and even fire. The bur oak is known to grow back after a blaze that can kill the whole top portion of the tree.

The bur oak’s acorns are large at 1.5” long, and have the lowest tannin level of all the North American oaks making them one of the mildest-tasting acorns.

Hardiness Zone: 3-8

Pollinator: Self-fertile but best yields when paired with another oak for pollination. Note that many oaks will readily hybridize.

Mature Size: 80’

Spacing: 80’

Soil: Can tolerate dry conditions and pH of 5.5-8.5

Sun: Prefers full sun but tolerates some shade

Flowering: Spring

Harvest: Fall