It’s more important than ever to know what oak you’re looking at because of the introduction of oak wilt to Long Island, which is a serious disease that affects all species of oaks (Quercus spp.). While all species of oaks are susceptible to oak wilt, the fungal pathogen (Ceratocystis fagacearum) doesn’t impact all oak species equally to the same degree. Species in the red oak group, in particular red oak (Quercus rubra), are most devastated by this disease and die within the first year or less upon infection. With species in the white oak group, however, a much slower progression of the disease occurs—it may be years before the infected tree dies. To learn more follow this link to Oak Wilt Risk: Distinguishing Red and White Oaks.

Leaf from the white oak group on the left, and red oak group on the right. Note the curved leaf margins and hair-like bristles that distinguish the two.