If you don’t yet have a compost pile, you’re missing out in a big way. First of all, composting gives us the opportunity to reduce the waste coming out of our kitchens. Food makes up almost 13 percent of the U.S. waste stream, and an even higher percentage of landfill-caused methane gas (a major contributor to climate change) because foods produce large quantities of methane as they break down. But perhaps even more amazing? Compost from the parts of your food that you don’t eat today can actually improve the nutritional value of the homegrown food you’ll eat tomorrow.
Scraps for Your Soil
To realize the benefits of these table scraps, work them into your compost pile, where they will break down alongside yard waste into garden fertilizer that you can apply directly to garden beds. To learn the basics of composting, visit the composting collection page. It’s incredibly easy. Some table scraps help deter animals when added directly to garden beds. We’ve noted these cases.
Benefits: Apples and apple pomace (the remains from juicing) contain a fair amount of potassium, plus some phosphorus. They decompose quite quickly.
Note: Avoid non-organic apple skins, which have been sprayed with pesticides. Make sure you balance the moisture and acidity of pomace with equal parts dry leaves and newspaper.
Benefits: Banana peels are a rich source of potassium (around 40 percent), some phosphorus, a little nitrogen, plus trace elements—all of which makes for strong stems in your plants. Banana peels also help activate the decomposition of other organic matter.
Note: Chop peels to speed breakdown.
Benefits: Dried potato vines, tubers and skins are a good organic source of many nutrients including calcium, magnesium, potassium, sulfur, many trace minerals and some nitrogen.
Note: Cut vines into smaller pieces, and use only vines that you are certain were not contaminated by late blight.
Benefits: Citrus fruit wastes contain a large percentage of potassium, a little phosphorus and traces of nitrogen. Citrus peels help deter small animals.
Note: Citrus peels are slow to decompose if not chopped into small pieces. To deter animals, chop up and leave peels near your plants on the soil surface.
Benefits: Green vegetable scraps are rich in nitrogen, vitamins and minerals. For example, lettuce is a good source of calcium and vitamins A, C and K.
Note: Most vegetable scraps decompose quickly, but if your compost pile is accessible to wildlife, it’s wise to cover newly added food waste with grass, leaves or other compostable material.
Benefits: Coffee grounds contain small amounts of nitrogen, phosphorus and potassium, plus trace nutrients. Slightly acid-forming, they are particularly great for plants that like acidic soil such as blueberries and rhododendrons.
Note: Use in moderation or along with a calcium supplement such as eggshells.
Benefits: Eggshells are an excellent source of calcium (lime) and micronutrients, plus phosphorus and nitrogen.
Note: Try incorporating crushed eggshells into planting holes when you set out seedlings. The calcium helps prevent tomatoes, for example, from falling prey to the plant disease blossom end rot.
Fish Bones and Scraps
Benefits: Fish bones are a great source of slow-release phosphorus and calcium. Raw fish scraps have been used for ages as a rich source of nitrogen. They are also said to repel insects from soil.
Note: Avoid using cooked, oily fish. Bury bones and scraps in beds rather than adding them to your compost pile.
Plant Nutrients 101
In this article, we address several common table scraps and the benefits each can make to plants. For this discussion, it’s valuable to have a basic understanding of a few major plant nutrients:
Benefits to plants: Healthy growth of stems and foliage; rapid vegetative growth; component of amino acids, proteins and chlorophyll
Benefits to plants: Important to seed, root and flower development; promotes vigorous growth; an essential component of DNA; important for protein synthesis; involved in the transfer and storage of energy for biochemical processes
Benefits to plants: Hardy growth; strong stalks; increased disease resistance
Jesse Vernon Trail is an author, horticulturist, amateur botanist and instructor. He’s a curriculum developer on gardening (with an organic/natural focus); health and nutrition; environmental awareness and concerns; sustainability issues; and natural history.