People often ask me why the oaks and other trees in California need to be tended. Oaks have been growing in California for many thousands of years, so why would they need our help now?
The answer is clear. The great oak woodlands and savannas of California are not the result of mother nature doing what she does best. The iconic oaks are largely the product of thousands of years of tending by Native Americans. It is well documented that the native people here managed the oaks with fire, keeping the ecosystem in an early successional state that is optimal for oaks. Acorns from the oaks were a primary food source for the native people of California.
Now-a-days, fires are no longer allowed to burn in many areas and the oaks and other trees are suffering. One solution, of course, is to reintroduce fire back into the ecosystem. Indeed, prescribed burning has been a successful management practice used by managers in Yosemite and Sequoia National Parks.
However, in situations where burning is not practical, there are other ways to achieve similar results but without all the smoke and flames. These protocols involve a suite of methods designed to mimic the effects of fire, as well as other land care practices of native people. These include some or all of the following:
• the removal of most shrubs and young trees from beneath the canopies of the oaks
• pruning of dead limbs and branches
• excavation of root crowns
• removal of mosses and lichens from the lower trunks
• removal of mosses growing on the ground around the oaks
• application of a mineral-rich spray or poultice to the trunks with degraded and split bark
• application of shell and volcanic ash fertilizers, enriched in trace elements, to the soil surface from the trunk to the dripline of the oaks
• application of compost, compost tea, and/or mulch to the soil surface from the trunk to the dripline
The specific methods and materials that are used depend on the type, condition, and situation of a given tree or grove. I find it’s best to treat every tree as a unique individual and avoid “cookbook” approaches to tree care.