The park has gorgeous old Oak trees- Coast Live Oaks and Valley Oaks that are many hundreds of years old.
Coast Live Oaks are evergreen and have rounded leaves with slightly spiny edges. Valley Oaks have lobed leaves and are deciduous. These are the most common Oaks in our area and many folks have them in their yards or neighborhoods.
I wanted to blog about them because they are so much a part of our lives in the Bay Area. Where I grew up in San Rafael we had Oaks all around our home and even one in the middle of the house! The home is actually built around a Valley Oak forming an "L" around the trunk. We climbed them, gathered the acorns to play games with and threw the galls at each other as kids. I have spent many happy hours gazing up into the branches of the contorted Oak covering our deck.
Living under the canopy of an Oak is not always easy. They are huge trees that drop leaves, acorns and spent blossoms. They are often the home of caterpillars and insects that can also cause honeydew drip, leaf drop and other assorted messiness. Yet, we thank them for the shade, beauty and bird activity that thrives in their canopies.
That is actually the most exciting fact about large trees- they are a giant environment and ecosystem in their own right. Supporting birds, moths and insects, bacteria and fungus that larger animals live on that in turn are food for even larger creatures, these trees are a big part of the food chain. Shelter and structure is also a part of their role as well as the action of the root system in preventing erosion.
You will often hear advice that Oaks should not be watered under the canopy and especially not at the base of the trunk. This is due to disease issues- crown rot, fungus' and even termite damage.
There are a lot of things that live in and among the Oaks that don't hurt them.
|Lichen on a twig|
does not harm the structure. Lichen is really a cool plant and I love the many colors and shapes it can have.
Often Oaks will have cavities where a branch has died out. The cavities may or may not be a problem for the tree- mostly not. These holes become homes for birds, bee hives, small animals and even other plants.
Do not fill the cavities with anything like concrete or tar- this can damage the trees. They heal up on their own.
Galls are kind of interesting too. They come in a variety of shapes and sizes and on an Oak you may find 5 or more different kinds of galls.
Another aspect of living below Oaks and other large trees is compaction. Trees do not benefit from having a lot of traffic running over their roots. Paving below trees is hard on the trees and the paving! Best to stay back from the trunks 8-10' or more with paving and path areas. This is usually impossible in our tight urban settings but if there is a choice this is the rule of thumb.
Last note on large trees and Oaks- attaching things to them isn't a great idea. Building a tree house? Use posts and beams around the trunk and branches rather than nailing into the tree. Hanging a pot, swing or sign? Allow plenty of chain or rope instead of using a tight loop so the tree can expand and surround the chain or rope with rubber to avoid abrasion. Remove tight tree ties or bracing so the tree won't be strangled or girdled over time.
Think of an Oak as a huge community supporting hundreds of organisms and providing oxygen for hundreds more. An Oak is more than "just" a tree it is a complex living being and structure that asks for little and gives and gives and gives. Amazing!