Grow your own bath or cleaning sponges, naturally. An heirloom variety, luffa gourd produces 3-7 in., light green, cylindrical fruits. Harvest them at the small stage and eat as a vegetable—or let the fruits mature on the vine, harvest and cure. When the gourd is dried, peal the skins and use the sponge for bathing, washing dishes or other household cleaning. Luffa vines can grow 10-12 ft. long—growing near a fence or trellis is recommended. In Northern regions, start gourd seeds indoors and transplant the young plants to the garden after danger of frost has passed. 120 DAYS.