how can I effectively kill an invasive sumac tree?

Answer 1

Oh boy, been there! If it is your tree you can spray it (if you can reach the foliage) with Roundup often, cut it down and keep after the shoots that will pop up. Hopefully with spraying before cutting, you'll eliminate a lot of suckering...but then, it is a sumac. Problem with spraying up into a tree is the drift can carry onto other plants.

Another thought is to cut it down and immediately begin treating the trunk with Roundup. First of all, not the premix stuff. We want the concentrate. You can use it full strength and paint it onto the stump...repeatedly. Or you can make a saturated mix: take a gallon of hot water and slowly stir in ammonium sulfate (22-0-0 fertilizer) until no more fertilizer will dissolve. Add Roundup according to the dilution directions on the bottle. Spray the stump. This solution doesn't last so use all. Remember Roundup deactivates when it reaches the soil, so it's not a drench. This same saturated solution can be used on those suckers that pop up.

Finally you can use a brush killer but I have trouble with soil transfer with that stuff so I much prefer Roundup if other plants are nearby.

If this is not your tree, but a neighbors, then a shovel on the suckers is all you are legally allowed to use. Any spray that kills the entire tree without your neighbor's approval can leave you open to a law suit.

Answer 2

I bought some stuff one year at walmart that you put on the open cut of trees and shrubs and it goes down to the roots and will kill just about anything. But I can't remember the name. I just go in there and read labels.

Answer 3

Fertilize it with mirical grow , or lime

THey like very acid soil