Identification Helps: This large, often majestic oak has deeply incised leaves, as shown in the photo on the left. Its bark is deeply furrowed in older trees. Twigs often have "wings," as shown in the right photo. Acorns are deeply enclosed in the supporting cup.
Preferred Growing Conditions in the Wild:Bur oaks can grow in both prairie and non-prairie conditions. On prairies, bur oaks are often found along prairie borders, or as specimen trees on the prairie.
Preferred Soils:Bur oaks can grow in most soils, preferring mesic (normal moisture) to xeric (dry) soils. It usually occupies alkaline soils.
Seasons of Growth and Bloom:Blooms right after leaves mature, in May. Acorns mature and drop after a single year.
Natural Distribution in Ohio: Found in all major Ohio prairies, and elsewhere in forests across Ohio.
Description and General Information: Bur oaks are the most common oaks on Ohio prairies, often appearing as large, majestic specimens. Like all prairie oaks (including black and white oaks), bur oaks at maturity have thick, heat-resistant bark that protects the tree from frequent prairie fires. Fires consume the stems of smaller oaks, but the trees grow back from protected roots.
Bur oaks have deep tap roots, making this one of the most drought resistant trees in Ohio.
Bur oak acorns have reduced tannin content, making them palatable to a wide range of wildlife species, including deer and turkeys. Blue jays commonly transport bur and other oak acorns out into open prairie and deposit them in the soil, thereby dispersing these oaks into new areas.