Island live oak
Quercus tomentella
Last reviewed: October 2026
Island live oak (Quercus tomentella) is a perennial tree native to CA. It blooms in March, April, and May.
Toxicity unknown
Island live oak (Quercus tomentella) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
low
Size
360"–600" H × 240"–360" W
Bloom
Mar, Apr, May
Native to
CA
Before you buy
Your city may pay you to plant this
Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 460 programs across 44 states, each with a link to the provider and the date we last checked it.
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Browse plants for this ecoregion
A medium to large evergreen oak with thick, glossy, deeply veined leaves and a dense, rounded canopy, native to a few island and coastal locations. Small greenish catkins appear in spring.
Growing Island live oak
Grow Island live oak in full sun and low water. Mature plants reach 360 to 600 inches tall and spread 240 to 360 inches wide.
Wildlife value
Host plant for California sister, gold-hunter's hairstreak.
As an oak, it supports numerous dependent insects including California sister and gold-hunter's hairstreak caterpillars, and acorns feed birds and small mammals.
Common questions
- How much sun does Island live oak need?
- Island live oak grows best in full sun conditions.
- When does Island live oak bloom?
- Island live oak blooms in March, April, and May.
- Where is Island live oak native?
- Island live oak (Quercus tomentella) is native to CA, per vouchered herbarium specimen records and regional native plant society lists.
- What butterflies or moths does Island live oak host?
- Island live oak is a larval host plant for California sister and gold-hunter's hairstreak.
Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
Ready to grow Island live oak? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.