Haven't heard of that...good idea to keep the herbicide in there. What are you wrapping it with? If you are successful killing Ailanthus, you are doing something right!I've had good results killin off Ailanthus by girdling them, wrapping the wound with Roundup poison ivy plus drenched cotton balls.
The hardest to kill's poplars, hands down, even Garlon drenched cotton balls just chased them around the complex for five fuggin years! Sprouts comin up in the middle of ponds!
Jomoco