We have two mature stag’s horn sumach trees in our garden. I love them, but they send out suckers into the lawn and beds. Ever since we scarified our lawn, the stag horn is all over it. Digging out the roots is not an option. What can I do?
Whether it’s bamboo or a stag’s horn sumach ready to take over your life, you need to dig a trench. Stag’s horn sumach (Rhus typhina) is notorious for suckering, and will do it whether or not you disturb the soil around it. It’s their way of getting around.
Start the trench just outside the drip line of the trees – the farthest point the leaves grow to. The trench will need to go all the way around the tree, but it needs only to be wide enough to accommodate a spade and about a foot or more deep. When a sucker appears, slice it off with a spade; and you’ll have to keep doing this to manage the situation. Some of the suckers in the lawn will try to grow into a new tree, but regular mowing and digging out any offenders should keep them at bay.
I don’t think this will work for your mature specimen, but it is possible to grow this tree in a very large pot, submerged in the soil with its bottom removed so that the pot acts as a barrier, but the tree can still access nutrients in the soil.
• Got a question for Alys? Email askalys@theguardian.com
