These kitchen throwaways make the perfect breakfast for your plants.
By Mary Jarrett
If you’re a serious recycler, you already know what to do with leftover apple cores, oatmeal, dryer lint, pet fur, toilet-paper rolls and slimy over-the-hill cilantro. You toss them into the compost pail and put the contents out for curbside collection. Or, if you make your own garden compost, you mix these scraps with the proper proportions of “green” and “brown” materials—and perhaps some red wigglers—and let the whole mess ripen, turning it occasionally until it breaks down enough to use it in your garden.
But what if you’re not that committed or patient, or you want to try something a bit offbeat that generations of home gardeners have sworn by? We’re not talking about dosing your garden with Epsom salts, copper coins, fish-tank water, pet food or human urine—all touted as plant supplements online. Instead, we’re talking eggshells, banana peels and coffee grounds, judiciously applied around certain types of plants without the wait for decomposition. Although the gardening experts we called shied away from endorsing such old wives’ remedies, these three substances have earned countless testimonials and even some grudging professional respect.
Mikl Brawner, co-owner of Harlequin’s Gardens in Boulder, doesn’t approve of dumping garbage directly on a garden. “Compost should contain a mixture of organic ingredients that have decomposed slowly and naturally,” he says. “Plants need a proper balance of nutrients, not one thing at a time. But eggshells and banana peels—those should be safe, and I’ve heard good things about them.”
Boulder County gardeners report success with these homespun supplements. For one woman in Niwot, who chose not to be quoted, eggshells and coffee grounds have helped produce a vegetable garden so wildly robust that she has to give away most of the food. In Boulder, William Brock tried the eggshell treatment after persistent problems with blossom-end rot on tomatoes.
“We really had issues with the heirloom varieties, especially the Black Krims and Purple Cherokees,” he says. “An old saw holds that if you put eggshells in the bottom of the pot, it would help prevent rot. I don’t know why that’s the case, but it really worked on last year’s crop. Not one case of bottom rot!”
The reason eggshells help is that they’re almost 95 percent calcium carbonate, and tomatoes (peppers, too) are susceptible to calcium deficiency. Here are a few anecdotal tips for trying them and other trashy treats to give your garden a lift. Remember, they’re no substitute for the balanced nutrients each plant requires, and you may need to test your soil.
EGGSHELLS
Nutrients provided: Calcium, which strengthens cell walls (much like building strong bones) and improves plants’ growth, vigor and overall health.
Plants that like them: Tomatoes, especially heirlooms; peppers; blooming plants
How to apply: Collect empty eggshells, wash them in warm water and drain. Dry them out by placing in a warm oven for 30 minutes, or in the oven as you turn it off after baking a chicken, cake, etc. Crush the eggshells, pound with a wooden spoon (kids find that fun), or grind in a blender, food processor or coffee grinder. Sprinkle around the base of each plant, ideally in early spring or fall, and work some of the shells lightly into the soil. Eating bits of eggshell may benefit mother birds that visit your garden. The shells’ sharp edges discourage slugs from crawling over them. Alternatively, you can drop crushed shells into holes you dig for starter plants.
Half-eggshells also make neat and nutritious little cups for starting seeds. Choose relatively deep halves from the pointier end of the egg, poke small drainage holes with a pin or nail, and fill with soil and seeds. (Of course, they sit perfectly in an egg carton.) When it’s time to pot or plant your seedlings, you can place each shell directly in the soil or potting medium for protection and a calcium boost.
COFFEE GROUNDS
Nutrients provided: Nitrogen, plus fatty acids and essential oils. Coffee grounds are only slightly acidic, with a pH of 6.5-6.8.
Plants that like them: Tomatoes, lawn grass, spinach and other leafy greens, roses, azaleas, rhododendrons
How to apply: To avoid mold, allow grounds to dry out in a compost crock or plastic container while you add to your collection. Dry coffee grounds can improve soil texture and increase plants’ vigor, growth and general health. Apply 1 tablespoon weekly around each plant and work the grounds lightly into the soil. When improvement plateaus, stop. You can also use coffee grounds as a mulch to deter rabbits and squirrels; slugs don’t like them either. But be careful not to apply the grounds too thickly, lest they form a water-repellent barrier. To green up lawn grass, lightly broadcast dry grounds among the blades before watering.
STEEPED TEA LEAVES
Nutrients provided: Nitrogen
Plants that like them: Acid-loving plants including roses, ferns and blueberries
How to apply: Tea leaves are somewhat more acidic than coffee grounds, so reserve them for acid-friendly plants. They lighten soil texture and may boost plants’ vigor, growth and overall health. Use them at times when plants are not actively growing. After brewing tea, save the loose tea leaves, or paper or silk teabags with tags and staples removed. (Used tea bags are also good for wiping down plants’ leaves.) Mix tea leaves into the soil directly or spread it on top like mulch.
BANANAS
Nutrients provided: Potassium, along with sulfur, magnesium and calcium, is released into the soil as the peel or fruit decomposes.
Plants that like them: Roses and flowering plants
How to apply: Banana peels and overripe whole bananas can be used interchangeably. Choose organic bananas, which won’t have been sprayed with dangerous pesticides, and take off any stickers. You can collect them in the freezer until you’re ready to apply them as-is or blended into a slurry. Lay a banana peel or two under the soil about 6 inches away from an existing rosebush. When planting a new rosebush, lay the peels flat in the trench. Don’t use bananas indoors because they will attract flies. (Aphids, however, hate bananas, and spraying a banana-peel tea on affected plants is said to be effective.) Outdoors, bury bananas up to 4 inches deep to deter raccoons and squirrels from digging them up.