When I was growing up, my grandfather used to go fishing to catch the evening’s main course. After scaling and cleaning the fish, he’d save their heads—quite icky to a little girl’s sensibilities—and plant them in his backyard garden. The fish remnants were (and still are) an extremely effective fertilizer because they boost soil’s nitrogen levels.

Casey Kellar, author of The Good Earth Home & Garden Book, has a not-too-messy alternative for organic gardening enthusiasts who want to give their plants a helping hand. She recommends mixing equal parts of water and tuna “juice”—the liquid you normally drain from canned water-packed tuna (about 1/2 cup each). Then add a drop of unscented mild detergent to the mix, and pour it into a bottle. Shake and use immediately.

It’s a bit stinky, Kellar admits, but she says plants absolutely adore her “fish fertilizer.” You can order her book through Amazon.com.