I buy from treeprotectionsupply.com out of GA. I've had good luck with the tree pro tubes staked with 1/2" conduit. Just planted 24 recently with 5' tubes. With 5' tubes they send some plastic mesh to go on the top of the tubes to keep blue birds from falling in. Why blue birds I don't know, but I've noticed they in particular like to lite on top of the 5' tubes around my place. With 4' tubes they claim they don't need the mesh. About 7 years ago I planted some saw tooths with some 4' tree pro tubes and those trees today are at least 25' plus maybe taller. Granted it was some great soil in that area but tree tubes are worth every penny IMO. They work better than fertilizer for a seedling.