|I have a beautiful old white lilac, with a bench under it as a focal point in my perennial bed. Each year I cut, pull out and have even tried Round-Up on the sucker roots of the bush. Today I pulled out at least 100 suckers 10 to 20 inches tall. How can I control this problem? I have put down plastic under the bench with mulch. They even come out past the drip line under the plastic. Any suggestions would be helpful.
|Unfortunately, it is the nature of lilac to sucker and their annual removal is a gardening tradition of sorts. There is not much you can do to minimize it beyond ensuring that the shrub is healthy and that the top is permitted to grow large enough to use most of the energy available through the root system. If you currently use fertilizer on the lawn surrounding the shrub or on the shrub itself, cut back, as this may also be encouraging the rampant growth. Regular mowing of the area may also discourage newly emerging shoot tips.