Most of central California falls into USDA-growing zones 9 and 10. The conditions here are too hot – and with not enough winter chill hours – to grow the ever-popular Northern red oak, which grows best in zones 3 through 8. Here are three oak varieties that can tolerate the warmer climate.
Live Oak
Live oaks are quite popular along the West Coast because they grow quickly, live for centuries, and are able to adapt to most soil types. They can grow well through zones 9 and 10, reaching up to 80 feet tall when mature.
Live oaks are known for their round, sprawling appearance; their curved and bending branches have unique character. They’ll adapt to full sunlight or partial shade and grow well along the street.
California Black Oak
Sometimes known simply as the black oak or Kellogg oak, this oak variety is highly adaptable, growing in zones 5 through 10. It grows slowly to a maximum height of 30 to 80 feet. Black oaks prefer well-drained soil, can tolerate some drought, and thrive in full sunlight. They really like to dry out in the summer, making the central CA weather suitable to their needs.
Sawtooth Oak
The sawtooth oak won’t likely grow in the warmer, zone 10 parts of central CA, but it will probably grow in zone 9. This oak variety has a moderate growth rate and thrives in full sunlight. Its mature height is 40 to 60 feet, and although it won’t tolerate alkaline soil, it adapts to most other conditions.
The sawtooth oak produces acorns earlier than many other oak varieties, and it also develops long, yellow catkins in the spring.
Here are a few tips to help keep your oak tree healthy in the warm and sometimes dry California climate.
Clear the Root Zone
Before you plant an oak tree, make sure the surrounding area is free from other plants and ground-covering grass. As the tree grows, mulch the root zone. These practices reduce competition for water and nutrients, leaving more behind for the oak tree.
Fertilize
Apply a slow-release fertilizer every two years to promote a healthy root system that will improve the tree’s ability to pull water and nutrients from the soil.
Trim Young Trees to Establish a Shape
Oak trees with a proper shape remain healthier because they are less prone to broken limbs. Shape your oak trees a couple years after planting. Your tree trimmer should aim to establish a single, dominant leader branch. As the tree matures, you won’t need to trim as often, but you should still remove damaged branches promptly to prevent disease and encourage airflow through the branches.
The best time to prune your oak trees is between January and March. Early trimming gives the tree time to heal its wounds before the warm summer months when resources are more limited and insects – which are often attracted to fresh wounds – are active.
The California black oak, live oak, and sawtooth oak all grow well in central California and add beauty to your landscape. If you oak trees on your land that are in need of trimming, contact
Community Tree Service, Inc., for a free estimate.
