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 Weather Station

Products > Quercus tomentella
Quercus tomentella - Island Oak

[2nd Image]
Habit and Cultural Information
Category: Tree
Family: Fagaceae (Oaks)
Origin: Channel Islands (North America)
Evergreen: Yes
Flower Color: Insignificant
Bloomtime: Not Significant
Synonyms: [Q. chrysolepis var. tomentella]
Height: 40-60 feet
Width: 20-30 feet
Exposure: Full Sun
Summer Dry: Yes
Irrigation (H2O Info): Low Water Needs
Winter Hardiness: 20-25 F
May be Poisonous  (More Info): Yes
Quercus tomentella (Island Oak) - A fast growing 35-50 foot tall evergreen tree with smooth gray bark that ages to a rougher brown with age. It is generally upright and nearly conical in its youth and broadening with a pyramidal crown with age. It has leathery 2 to 4 inch long elliptical shaped leaves, dark green on top and blue-green with tan hairs below with the margins having sharp widely spaced teeth. The large inch long acorns with a rounded apex sit in a warty thick walled cup and ripen in fall. Plant in full sun to part shade and give occasional to very little water. It is hardy to around 10 F and useful down to USDA Zone 7. It is more lush and upright than coast live oak, Quercus agrifolia, but still quite drought tolerant. Las Politas Nursery in Santa Margarita, CA reportedly had their 50 foot tall tree freeze to the ground in the December 1990 freeze at about 6-8 degrees F, only to sucker back up and "grow back as good as new". This oak is native to 5 of the California Channel Islands (Santa Rosa, Anacapa, San Clemente and Santa Catalina) as well as Guadalupe Island off of Baja California where it typically grows in the lower portions of steep canyons and occasionally along the upper ridges from 300 to 2,100 feet in elevation. It is considered a relic population that originally had a wider range when the west coast was warmer and moister. The name for the genus is the old name know to denote oaks and was derived from the Celtic words 'quer' meaning fine and 'cuez' meaning tree. The specific epithet comes from the downy hairs or tomentum that covers the newly emerging leaves. There are great examples of this tree planted in Santa Barbara area, including a very attractive specimen in front of the Goleta Water District Office at the corner of Puente Dr. and Hollister Ave and in Stow Park in Goleta and large beautiful trees at the Rancho Santa Ana Botanic Garden and the UC Davis Arboretum. The image of the tree pictured on our 2nd image was taken at the La Huerta Garden at the Santa Barbara Mission. This tree and 3 others were planted by Mission friars who reportedly had collected seed on Santa Cruz Island in the 1970's. The largest Island Oak known in a cultivated setting is a tree in the Arroyo Section at the Santa Barbara Botanic Garden. This tree, planted in in 1965 was 52.5 feet high with a crown spread of 60 feet and trunk circumference of 91 inches and is listed in the California Big Tree Registry as National Champion Island Oak. We have grown this species continually at the nursery since 1986 from seed collected from a grove in a private garden in Santa Barbara.  The information on this page is based on our research that has been conducted on this plant in our nursery library, from online sources, and from observations made of the crops growing in the nursery, plants in the nursery's garden and those in other gardens where we have observed it. We also have incorporated comments received from others and welcome getting feedback from those who may have additional information, particularly if this information includes cultural information that would aid others in growing Quercus tomentella.