Q. I had three Black Locust trees removed but now sprouts are growing from the extensive root system. Is there a way to eliminate the problem?? Also, there is one 50ft tree on the property. I was wondering when and how do I trim it? Thank You Rich Brown – Tacoma, WA
A. You are facing an uphill battle against the disposition of the Black Locust tree. Although many plants can send up root suckers from shallow roots that have been injured (e.g. by a mower blade) Black Locust produces suckers without provocation. This is because the tree uses this as mode of reproduction. This allows the trees to make dense stands that crowd out competing plants. So there is little chance you can eliminate the problem from the living tree. Instead you may try to mitigate the problem using a product I mentioned about 3 months a go called Tre-Hold. This is a plant hormone based spray that inhibits suckers both above and belowground. A certified professional with proper licensing will be able to advise you on the timing of the spray(s). A professional should apply this because any drift of the hormone spray can affect non-target plants. Now as far as the trees that were removed you can either keep the sprouts cut down regularly and roots will exhaust themselves eventually or you can have a professional apply a non-selective herbicide to the fresh re-growth so that it will kill the root system.