make cages out of wooden steaks.. build them 42" high.. and 21"-24" wide..
You will need 4 steaks cut to 42", and 8 pieces cut to 21-24".. nail first steak to supporting steak at the top of long steak.. nail the second supporting steak about 18" down..
This gives plenty of room to place wooden cage at least 6" into ground..
It also will hold up longer and will give the Toms more support.