We had a water oak that we removed. We tried killing the trunk, which didn’t work, and we have millions of sucklings growing in the yard. How can we kill them without killing the lawn?
The Gardener’s Answer
Hello, Marsha in Florida: Quercus nigra goes by many common names, including water oak. In some zones, this tree is considered weedy and I assume this may be true in your area. Since you removed the top of the tree but the roots are still alive, it is not the acorns but the suckers that have sprouted in your lawn. The abundant suckers are a result of stress and the tree is using all of its stored-up energy in hopes of surviving. It is pushing out growth in order to photosynthesize, but if you do not allow this to happen the roots will not survive. Slowly but surely this process will work, but you have to stay on top of it and not let the suckers get out of control. If the tree can’t photosynthesize then it will eventually die. Since you have so many suckers and they are in your lawn you can just mow them down. This method may not be the best choice with a healthy tree but in your case it seems to make sense. Given the numbers you are dealing with, hand pulling or painting each sucker with glyphosate is not feasible. Tree roots can be very aggressive and this is true even after the trees have been removed if the stumps are not ground out. So, this would be one option for dealing with the suckers. Having the stump ground out will help prevent any suckers from forming. This would be the most expensive but most effective method. If you decide to go this route, it is always best to hire a certified arborist.