I've tried several different things for fuel (burlap, wood shavings and dry hay) but none of them lasted for more than four or five hives. Then a friend showed me how he uses alfalfa pellets. He puts about an inch of shavings into his smoker, lights it, pumps it to get the shaving going,then adds the pellets. Once the pellets are smoking he puts grass in the top to keep the pellets from falling out. Takes about five minutes to light it properly, but then you can use it all day. A bag of alfalfa pellets will last a long, long time.