Complete fertilizers often contain the three essential plant nutrients—nitrogen, phosphorus, and potassium—as well as a number of beneficial micronutrients that can assist with photosynthesis. Plant foods, on the other hand, usually contain only a few of them. (Think of them as a targeted supplement for your greenery.) Here, Kelly Wilkniss, gardening expert and host of My Soulful Home on Smart Healthy Green Living shares her simple, three-ingredient recipe for well-rounded homemade plant food. Before we dive in, it’s worth noting that some plant biology experts have concerns about applying kitchen scraps directly to soil, as it can damage plants if not done with care and know-how. Beginner gardeners might want to turn around here, but more experienced green thumbs can move ahead and get those eggshells ready. If you notice any strange leaf spotting or creepy crawlies after buying the blend, switch to a store-bought fertilizer or try another option. Soaking banana peels in water for a few days, for example, will leave you with a potassium-rich liquid you can use to water your plants. From there, you can throw those soggy peels—along with your eggshells, coffee grounds, and any other organic food or garden waste you have around—into your compost bin or vermicompost setup. Eventually, your scraps will decompose into a super nutrient-dense soil that you can spread over the top layer of your garden. Green veggie scraps and grass clippings tend to be particularly good for composting since they’re high in the nitrogen that plants love so much. Alternatively, you can also make a liquid plant food by diluting 1 tsp. baking powder, 1 tsp. Epsom salts, and ½ tsp. ammonia into a gallon of warm water. “This mixture will provide tiny amounts of magnesium and nitrogen, but no micronutrients, so it is not a complete fertilizer,” garden writer Barbara Pleasant tells mbg. Emma received her B.A. in Environmental Science & Policy with a specialty in environmental communications from Duke University. In addition to penning over 1,000 mbg articles on topics from the water crisis in California to the rise of urban beekeeping, her work has appeared on Grist, Bloomberg News, Bustle, and Forbes. She’s spoken about the intersection of self-care and sustainability on podcasts and live events alongside environmental thought leaders like Marci Zaroff, Gay Browne, and Summer Rayne Oakes.