Killing box elder trees

[Brad H.]

Ok guys I need some help. I have some box elder trees choking out some pine trees I planted a few years ago. If I cut the shoots they come back up twice as thick. Right now they are about 4 feet tall. If I cut them they will shoot out and be two feet tall by the end of summer. I even cut them clean at the base and brushed on roundup thinking that would kill the root system. Notta. How do you kill these things!

[hoseromon]

There is a killer for trees that you paint on after cutting at the base. I don't remember what it is called though. I remember it was purple color so you could make sure you covered everywhere. That's the best I got it has been some years

[bk]

A few years ago I used an industrial version of Roundup that was made to paint on freshly cut stumps to prevent re-growing.  Got it at the local farmers cooperative.  My version was a dark green.  Worked very well on box elder and poplar.  Remember it was nasty crap - needed to wear rubber gloves when painting it on.  Freshly cut seemed to be the key as stuff I had already brushed out but then coated didn't die.  Not a big fan of a better world through chemistry, especially now that I raise bees, but this stuff worked.  End of story.  Good luck and keep us posted.

[jimo]

Tordon is a blueish green color chemical that you paint the stump with after you cut at ground level. It is very deadly. Use it in late summer when trees are starting to flow to the roots. I use it on autumn olives here and it is very effective when many other things aren't. You can use it other times of year but in the spring when trees are flowing from the roots to the top the stump will flow and wash the Tordon out into the soil. Then other things around are killed. Using in August and September I have around a 95 percent or better kill rate and don't get the damage to surrounding plants. Hope this helps.