Island Oaks

Island Oaks, Santa Rosa Island
Photo by Marla Daily

Island Oaks, Santa Rosa Island

Island Oak

Island Oaks (Quercus tomentella) are the rarest of all California oak trees. They are found naturally only on five of the eight islands: Santa Cruz Island, Santa Rosa Island, Anacapa Island, Santa Catalina Island and San Clemente Island, and on Guadalupe Island, Mexico. The island oak is a relict of an ancient California when the climate was warmer and more moist.

In the News~

September 15, 2019 [edhat]: “ Island oak, the rarest oak in California, also happens to be one of the best broadleaf evergreen trees to plant in Santa Barbara, because it is such a stunning shade tree and because it is native to our area. No adaptation to our Mediterranean climate required! Also called the Channel Islands oak, it is now only found naturally on five of our Channel Islands (Santa Rosa Island, Santa Cruz Island, Anacapa Island, Santa Catalina Island, and San Clemente Island), as well as on Guadalupe Island (off the coast of Baja California). However, the fossil record shows that, until about 3 million years ago, it was once widely distributed on the mainland of California, on the coast and up to 100 miles inland. In the 1980s, commercial propagation of the Island oak was started in a Goleta wholesale nursery; since then, it has been planted in Santa Barbara gardens and streetscapes in ever increasing numbers. Island oak is a medium- to fast-growing tree which can reach a height of over 30 feet in about 30 years, with an ultimate height of 40 to 50 feet. Its outstanding characteristics include its dense pyramidal crown and easy maintenance. It is often low branching and relatively wide, providing sheltering habitat for our wildlife and casting a circle of dark shade, which is much appreciated by all when the weather is hot.”