Here in Northern California, our native oaks are some of the most magnificent trees that adorn our area. What’s better than kicking back and enjoying the shade of a sprawling oak tree?
Protecting Our Native Oaks
Our area was once covered with these majestic trees. But over the years, development and profitable enterprises have taken their toll on these native giants. Our over twenty indigenous species of oaks have been foundational feeding and nesting habitats to our native wildlife. Oaks are also drought tolerant, fire resistant, and require very little irrigation. But with SOD, oak root fungus, and other perils, the care and maintenance of our native oaks are more important than ever.
Understanding the Issue of Oak Root Fungus
It’s important to understand that oaks don’t require irrigation in the dry season. Our oaks thrive in our natural conditions and the fungus remains dormant during our dry summer months. Winter rains and overwatering bring the fungus to life. If water is applied to an oak during the dry season, the fungus has a breeding ground caused by the combination of water and warm air. Letting fungus infect our magnificent oaks can cause them to weaken and die.
Removal of Any Competing Vegetation From Root Crown
In order to protect our native oaks, it’s important to remove anything from around them that can trap moisture around the roots. Plants that grow near the root crown such as ivy and grass can harbor too much moisture, giving the fungus a perfect place to breed.
All competing vegetation should be kept out of the drip line of the oak other than drought-tolerant plants that won’t require water. A good way to keep grass and plants away from the oak roots is to lay a thin layer of mulch around the tree making sure to keep the mulch away from the root crown itself.
Removal of Excess Soil
Oak root fungus growth slows with exposure to dry air. Built up soil can hold excess moisture and, consequently, the fungus. Removing excess soils from the root crown will expose any fungus and take away the possibility of having too much moisture around the roots.
No Irrigation of Water Build Up
Ideally, no irrigation or other vegetation should be within ten feet or more of the trunk of an oak. Never allow water to collect around the root system or allow any irrigation to spray the trunk. Proper pruning should be done during the winter dormant period.
Nature as Fertilizer
Mature oaks don’t require much fertilization. Any leaves that may fall should be allowed to decompose under the tree in order to supply natural nutrients. If the oak shows yellowing leaves, it may lack needed nutrients or may be suffering. This is when a professional Palo Alto arborist should be called.
Call a Professional
If you are unsure about the oaks on your property, call the Palo Alto tree care specialists at Bay Area Tree Specialists. We can assess your oaks for any crown root infections and suggest ways to protect them. Let’s keep these natural resources healthy in their native habitat so we can all enjoy them for years to come.