hi i have 2 sycamore tree stumps 2 1/2 to 3 feet wide,i want to kill them because 1 is starting to sprout again,someone mentioned drilling holes in the stump and putting some pellets in the holes,but i can't seem to find any anyware,all i get in a search is the DEEP ROOT TREE KILLER,does anyone knowwhere i can get it please?i have tried my local garden centre,but they have'nt got any,i don't really want to go to the expense of grinding them out.thank you kaz44