Coast Live Oak - Quercus agrifolia (seedling)

The Coast Live Oak (Quercus agrifolia) is a beautiful evergreen oak that grows predominantly west of the central valleys, as far north as Mendocino County, and as far south as northern Baja California in Mexico. This tree typically has a much-branched trunk and reaches a mature height of 10-25 meters. Some specimens may attain an age exceeding 250 years, with trunk diameters up to three or four meters.

Coast Live Oaks are fairly easy to grow. Water 1x per week the first year after planting, decreasing to about 1x per month after the first year, until the tree is about 10 feet tall. After that, it’s best to avoid direct summer water entirely. In areas with less rainfall, best to plant Coast Live Oaks near an irrigated area. They’ll get the water they need by stretching their roots out to the wetter area, but they’ll keep the area close to their trunk nice and safely dry. Once they get their roots into the wetter areas, they’ll grow rapidly and stay healthy looking all year round. Coast Live Oaks prefer to have their roots shaded, so it’s a good idea to surround young specimens with mulch, rocks, or smaller native plants that won’t crowd out the young tree trees but will provide shade to the roots. The best mulch is a thick layer of oak leaves. Don’t fertilize oaks. They’ll amend the soil over time with their own leaves and build the natural mycorrhizal fungus in the soil they need to thrive. Gradually, they become islands of natural fertility that improve the health of the nearby plants.