Things You'll Need
Sumac is a shrub or small tree with many varieties. It is often used as an ornamental plant in the home landscape and provides brilliant fall foliage and attractive fuzzy fruits. There is also a poison sumac, which causes epidermal distress in those that come in contact with the plant. Sumac grows slowly from seed but it does spread quickly from suckers. Suckers arise from vegetative sprouts attached to the roots of the plant. Each sucker will become another plant. Controlling the spread of sumac may require a targeted herbicide or complex and repetitive mechanical measures. Note that strategies involving touching the plants should be done on non-poisonous sumac only; the Children's Hospital of Philadelphia warns that if you are dealing with poison sumac, use herbicides only and do not touch, dig up or burn the plant.
Cut off the flowers in spring. The tiny green flowers are insignificant but will become larger furry berries containing seed. The birds eat the berries and spread the seed, in essence planting it. You can also wait until summer and cut the clusters of berries off the sumac before they begin to ripen. Remove flower or fruit back to the next growing point.
Identify the suckers and dig down until you find the root. Follow the root back to the plant and cut it out. This will remove the existing bud point that would have formed suckers, but temporarily -- it will be back. Sumac control has to be done annually in this manner.
Prune off the suckers with loppers, leaving a small amount of stem. Use a 20-percent solution of glyphosate mixed with water and spray the stump or stem. Be careful not to spray other foliage as glyphosate is a nonselective herbicide and will kill any plant that it contacts. The herbicide is systemic, which means it will kill the entire plant.
Use triclopyr herbicide on thin suckers in areas where you can easily treat every sucker. This herbicide will kill the suckers but not the plant unless you treat the parent. Spray triclopyr mixed with horticultural oil at the rate that the packaging recommends. Target the base of the sucker stem. There is no need to cut the suckers prior to treatment, and you should see results within a week.
Mow off the suckers when they invade the lawn. This is a temporary solution as the underground root will still sprout. Over several seasons, the constant mowing will reduce the vigor of the sprout, and it may die. However, another may sprout in a different location.
Follow all safety precautions recommended by the manufacturer when using herbicides.