Yikes a 15' deep root? how man of them do you have? weeds wise? I wonder say if you have what 20-30 plants spread out it may not be that hard but. Take one of them 4-5' tree feeding rods.it a rod that a hole in the end that with the help of water from a hose. will drill itself a nice deep hole so you can feed the roots of trees. You could do that at or near each plant and the fill the hole with poison. used motor oil or what ever. That should kill the plant down deep enough that it wont come back. or come back easy. with 5 feet of poisoned dirt above it to come through.
used motor oil?....I don't think so.... the county doesn't even want me to keep them around in jugs, much less pour in the ground. Anti-freeze maybe......:Brow: Bruce
We have been fighting canadian thisle forever up here. Burning-tillage=antifreeze-oil- or whatever will do nothing but kill the top plant.Find out what the county is using and if it is a permanent kill or just a kill for now thing. They will grow faster than the grass if they are only mowed down. Good Luck and for that kind of money maybe you should go to a farm store and see about getting you own little sprayer that you can mount on a four wheeler or riding mower or something. These only sell for about 300 dollars ED K
