The best advice for maintaining oaks is to leave the environment around them as natural as possible. Anything done to modify the environment will have an impact on oak trees. However, when modification is necessary there are certain mitigation measures that will reduce the impact. It is okay to landscape under the drip line of oak trees with certain restrictions. Plants should be chosen which do not require summer irrigation and should not develop such a thick root and foliage mat that do not allow sufficient water permeability and gas exchange.
Many native species are excellent landscape plants for use under oaks.
Still, it is advisable to landscape away from the trunk. Vines should not be allowed to grow up the tree trunk. Pruning of oak trees is normally not necessary and should typically be limited to the removal of dead, weakened, dangerous or diseased branches with no heavy pruning at any time. Excessive pruning may stimulate rapid new growth subject to mildew or other related diseases and should be avoided. Oaks are a characteristic part of much of the California foothills.