I've posted several times before on this problem.
I had a black acacia tree ~16 in diameter. I pruned it heavily ~7 yrs ago and it sent up HUNDREDS of root suckers every year. About
1-1/2 years ago I took it down completely, leaving a stump ~10 inches above grade.More suckers. LOTS of suckers. It's ruined my lawn and garden. Round-up weakens the foliage but won't kill them. I finally used Ortho "Poison ivy & Tough Brush Killer" late last year. It seemed to kill them but we'll see if they come back.
'k, here's the Q: I got a powder stump killer. Directions say to drill 1" holes all over. I got a 1" bit and it won't go in even an inch (wood too hard, even after 1-1/2 yrs). So I tried a 1/2 in bit. After 3 holes to 10 inches it broke off.
Any ideas how to killthis stump and stop the suckers?
Thanks a heap,
-Zz "Zz Yzx" rhymes with "physics"; or " Isaacs" if you prefer.