Is your soil looking lackluster? Rich, earthy compost is just the right tonic for your garden beds. What is compost? It’s a mixture of whatever goes into the compost bin, all decomposed into useful, rich humus by big animals like worms and microorganisms like friendly bacteria. Into the bin go food scraps, shredded paper, leaves, and lawn clippings. Depending on your composting system, after a few weeks to a few months out comes earthy, porous compost that is ready to enrich the soil in your garden.
The Benefits of Compost
It’s a small miracle that soil can form from food and garden waste. Many of us throw out the stuff, thinking that it is garbage. Far from it. Food and garden waste is not waste at all, nor should it be wasted. It is useful raw material for your garden.
What does compost do? Compost adds microorganisms and bigger invertebrates to your garden. While we are all pleased to find worms in our gardens because we know that they turn leaves into soil, you may not be aware that most soil life is invisible or barely visible to the eye. Friendly bacteria and tiny invertebrates work away at the soil, turning it from food scraps into rich and fertile humus. This process frees up nutrients that plants can access. Composting happens in nature, and it can happen in your garden as long as you return organics to a bin or other composting system instead of sending them into the waste stream.
Compost adds air and water to the soil. Now, you might think that soil is made up of little brown bits of leaves and rock, and you would be right. However, between those little brown bits are equally important spaces. Plants need air and water to grow. Their roots need spaces in which they can move downwards into the soil. A healthy, compost-rich soil is porous and water will soak into the spaces in the soil, providing backup moisture for those hot, sunny days. If you’ve seen tomatoes wilt in the summer sun, you know the importance of moist soil.
How to Compost
Think of composting as a recipe. To compost, you need nitrogen, carbon, oxygen, and water. Where do you get all of these items?
Nitrogen is what many people call green waste. Grass clippings and food scraps have more nitrogen in them than average. The microbes in the compost pile use nitrogen to make protein. These nitrogen-rich materials also tend to be full of water, so a pile with adequate nitrogen will rarely be too dry.
Carbon comes from what people call brown waste. Leaves and shredded paper contain a lot of carbon, and they are commonly used in compost bins. One of the most common mistakes that the beginning composter makes is to focus only on what is available in the home. In the spring and summer, we have plenty of vegetable and fruit scraps and very few fallen leaves. However, when you neglect to put carbon into the bin, it gets quite mucky and smelly from the wet, nitrogen-rich green material. The microbes in the pile use carbon for energy. You want energetic, hard-working microbes in your compost bin! Remember your carbon, and you’re cooking.
Cooking is what compost does when it contains everything that it needs. Bacteria do their work in the bin, breaking down yard and food scraps into useful materials for plants. In the process, they release heat through microbial activity. This heat makes the compost a poor place for flies and weeds to thrive, and it’s a good sign that your compost is functioning as it should. Hotter bins also make finished compost more quickly. After the pile has started to cool, it is important to turn or aerate the compost with a tool that punches holes down into the compost pile. This adds oxygen to the compost bin.
For more information on composting, check out this site on how to compost at home.
Using Compost In the Garden
When your compost is ready, you’ll be eager to move it into your garden. You will find that you have less compost than you had garden waste. As the microbes synthesize garden waste, the chunks become smaller and the humus becomes dense. This means that you may need to choose the best place to put your compost: there may not be enough for the entire garden.
The vegetable garden is a logical place to put your finished compost. The nutritional value of our food is influenced by what is in the soil, and the better the soil, the more vigorous, healthy, and nutritious our food.
Use compost to prepare garden beds in the spring or before you put in a winter garden. Dig compost into the top layer of garden soil. After you have planted, you may want to use compost or compost tea as fertilizer and top-dress the plants with a thin layer of compost. For new and delicate plants, add a bit of compost around the plant to side-dress it with a good helping of nutrients and microorganisms.
In the fall, you can also use compost as part of a mulching system. Place the compost on the soil and add a cover crop like fava beans or winter rye. The plants and the compost together will protect and enrich that soil so that it will be even better after a long winter of rain and snow.
It seems odd that we buy soil and throw away food waste, paper, and leaves. Save and savor your garden and home waste by turning it into compost. This compost will nurture both new and established plants in your garden. When you raise healthy plants, you reduce your use of pesticides. Healthy plants in a diverse garden ecosystem are plants that are more resistant to diseases.
Compost also boosts the health of your soil, and this supports a diverse garden ecosystem. When bugs and birds are welcome parts of the garden, these predators eat many other bugs that eat your plants. Compost is an essential part of an organic gardening system. Who knew that such great benefit could be had from the scraps of yesterday’s dinner?
Tricia Edgar loves her small garden. She is an organic gardener who is intrigued by permaculture, straw bale and cob building, and green roof design. She also runs a sustainable skills mentorship program.