It’s the first week of March. The days are getting longer and the weather is warming up. All your deciduous trees are bulging with buds waiting to unfold into new leaves. However, your supposedly “evergreen” Coast Live oak looks terrible. It is shedding leaves like crazy and the canopy looks sparse. You wonder, is it diseased? Or is this normal?
Facts about Coast Live oak foliage
A leaf on an evergreen oak (also called a live oak) is retained for 2 to 4 years. The older leaves are often shed in spring as the new leaves are forming. This can cause the tree to look sparse until the new leaves have bloomed. So waiting until the end of March middle of April might solve the problem. Or at least confirm that the dropping of leaves is normal.
Flowers of the Coast Live Oak
In addition to the normal early spring leaf drop is the production of flowers. Coast Live oaks are monoecious (your new word for the day!) which means it has both male and female parts. The male flowers are pendulous catkins 2.5 – 4 inches long and produce pollen that is wind-driven. The female flowers are inconspicuous, less than a quarter-inch long, with 1-3 clustered together. The male catkins are light brown and from a distance, the abundance of them throughout the tree can make the oak seem like it is browning. Once the catkins expel their pollen and fertilize the female flowers they will drop to the ground, create a mess, but make the tree look a whole lot better!
Other Reasons for Sparse Foliage
If your Coast Live oak continues to look sparse well into June, it may have other issues. Root loss is always suspect in cases like this. Nearby construction where roots might have been damaged can affect the trees’ leaf production. Disease and insects can also affect a tree’s foliage production. At this point, it helps best to consult with one of our
arborists.