Photo by Cathrin CallasCoast Live Oak (Quercus agrifolia)
in the San Carlos Native Plant Habitat Garden
San Carlos, California
California Native
Enjoy the deep fragrant shade under this iconic and majestic tree. Some people feel embraced by these monumental and gnarled trees which are the very picture of grace and strength in the coastal landscape of California. This particular tree is over 100 years old and graces the native plant garden established and cared for by the San Mateo Master Gardeners.
What is a coast live oak?
Of the 20 varieties of oaks in California, this is the only one that can live near the coast. It is called "live" because it does not lose its leaves. It likes the fog, and has adapted to our climate of dry summers and wet winters.
It is wind pollinated. The fruit is an annual acorn. The male flowers are the hanging catkins, and the female ovary grows at the leaf junctions. Their lifespan averages 300 years.
Importance in the eco-system
Oaks are keystone plants, natives that are essential to our ecosystems because they support 90% of the caterpillar species that allow birds to reproduce and support our native bee population. In fact, 270 species rely on these trees for habitat and food, including birds, bees, butterflies and mammals.
Acorns were a basic food source for native people who lived on this land - The Ramaytush Ohlone.
Oak roots contain proteins and enzymes that regulate water and nutrient uptake which improves soil conditions.
In the 1880's San Carlos manufactured bricks shipped to San Francisco to build Fort Mason, the Palace Hotel and San Quentin. Not only was the soil here good clay for bricks, but coastal oak trees were most likely burned to fire the bricks in the kilns.
In your garden
If you are fortunate enough to have one of these magnificent trees in your landscape, you certainly want to take good care of it. Here are some basic tips:
Keep the land around them away from any irrigation or watering. Planting a lawn and watering it can result in your beautiful oak getting an irreversible root fungus that will eventually kill your tree.
Keep a house foundation at least 20 feet away from an oak.
Keep all plants 4-6 feet away from the trunk.
Let natural leaf drop serve as the mulch to nurture your oak.
