The Bur Oak is in a word—massive. It typically stands 70-80 feet but can reach heights of over 100 feet. Its rounded crown is often wider than the tree itself. It is an ideal shade tree and one of the slowest growing oaks, typically adding only 12-inches per year.
Leaves appear in early spring and are three to twelve inches long and two to ten inches broad. They have five to nine lobes.
Flowers appear shortly after the leaves. They are very small greenish-yellow catkins, with male and female flowers occupying the same tree.
The Bur Oak has the largest acorns of any North American oak. They are typically up to two inches long and 1-1/2-inches broad. The tree is sometimes called the Mossy Cup Oak because the acorn has a large, fringed cup. Acorns fall from the tree from August through November.
The Bur Oak requires full sunlight to grow and can be planted in a variety of soils; acidic, alkaline, well-drained sandy or loamy, wet and clay soils. Hardiness Zone: 3-8.