I buy the small bags of moss (not the Spanish moss, but long fiber peat) at the dollar store to put in the bottoms of pots. Not only does it keep the dirt from falling out of the pot, it also helps to conserve moisture. When it's time to repot, I put the plant, moss and all into the new pot. It eventually breaks down, but will help ease the shock of transplanting as the roots are still in 'familiar surroundings'
