I'm guessing you're using soil so, .....a 300 gph water pump (30-40 bucks) some nylon or poly tubing (3/8 to 1/2 depending on the fittings on the pump (CHEAP) some drip nozzles (about 5 bucks at lowes) and a timer for the pump ( 6 bucks at lowes). You could just lay the hose across the tops of your buckets, and zip tie them down so they don't move. Test it out before you leave, and set the cycle accordingly. I'm sure somebody has a better way, but that will work. You're looking at about 50 bucks all together.