My 12 year old Cornus has been sending up suckers for years now under the base of the tree. The leaves of the suckers are different and grow straight up so maybe they’re coming from the original graft.I keep cutting them but more grow in their place and are spreading right out under the tree. What can I do? The tree is surrounded by gravel.
Where you have gravel, you could remove all the exisiting suckers, then all the gravel and lay out Mypex or similar weed-control sheeting and replace the gravel. The sheeting with exclude light and prevent the suckers growing and the gravel, if heavy enough, will prevent the suckers ligting the fabric.