Does anybody know how to get grass to grow under oak trees?
Choose the right grass and water it sufficiently. You have to remember that the tree is sucking a tremendous amount of water and doesn't leave much for the grass. We have St. Augustine under our oaks, but the trees range from 50-100 years old and are trimmed up at least 15-20 feet from the ground to allow the sun to get under in the morning and again in the afternoon.
It is also necessary to thin out the limbs inside the drip line of the canopy -- anything that is pointing up or pointing in -- any branches that somehow rub against another. All of the branches should be growing outward. This pruning does two things: 1) keeps the tree vigorous and allows airflow through which helps it defend against strong winds; and 2) permits filtered sunlight to the ground.
Check with your local seed dealer or county extension agent on the shade grasses that thrive in your area.
We have this problem too, someone told us it won’t grow due to the oils from the leaves or something like that. We did plant some St. Augustine next to the patio were some of the oak branches hang down over it, and it has done okay..just does not spread. I live in Ga. and have clay soil, so don’t know if that has something to do with it to.