By UC Master Gardener Cynthia White
As Thanksgiving moves us toward the wonderful holiday season I’d like to pay a bit of tribute to the mighty oak tree. Scientists have determined that the oaks appeared about 65 million years ago and that today we have about 500 species, twenty of which are native to California. Oaks thrive in our hot, dry summers and cool, wet winters and are considered to be a keystone species. That means that oaks are part of the glue that hold our ecosystem together.
Oaks provide food, water and shelter to species of 5,000 insects, 105 birds, 105 mammals, and 58 amphibians. The thick bark of the oak provides built in protection from fire so as a long-term member of the landscape it has a lot going for it. Oaks generally can be expected to grow to about 40 feet although there has been specimen that spread as much as 80 feet.
The leaf litter that accumulates beneath the oak tree provides a multitude of benefits in our communities. It filters water and helps prevent soil erosion by buffering the impact of rainfall. Leaf mulch helps retain soil moisture, lowering soil temperatures and discouraging weeds. All water in California flows through oak woodlands.
I grew up in Chico and remember the famous Hooker Oak that lived nearly 500 years and spanned nearly 100 feet. When a drought era north wind took it down several years ago the ground must have trembled with it’s might.
If you want to plant an oak in your yard, remember the size and space required. Most trees planted in areas next to the gutter known as a mow strip will quickly outgrow its allotted area and you will never be happy when it finally reaches a point it must be removed long before it has reached its potential. If you have grandchildren, you can rest assured that they will be enjoying the bounty of the oak trees you plant today for their lives and those for many future generations.