Choose sturdy ones as thin ones get brittle soon and break, write on the dull side of the plastic with an ordinary pencil, stick it in the pot tightly to the side, then force the top in an inch or so by lodging a piece of bark or whatever, between the label and the rink of the pot to keep it from getting broken and the name of the plant lost; holes can be punched for tying with a hot ice pick; before writing on them dip them in a mix of water and detergent; or, sterilize them for some hours in 10% bleach before re-use. OR85-168; RMH