Trench composting is a way to compost kitchen and garden waste, including weeds, that requires almost no work on your part and enriches your soil in as little as one month. This composting method is completely invisible, completely undetectable by smell, and can fit just about anywhere in your garden. The best part of all? It requires no turning whatsoever.
What Is Trench Composting?
Trench composting is simple. You dig a trench—or any shape hole—approximately 12 inches deep in an empty space of your garden, add roughly four to six inches of compostable materials, such as kitchen scraps, spent garden plants, small prunings, thinnings, and weeds, and bury them with the soil you dug out of the trench or hole.
The next step is...well, there is no next step.
The best reason to compost in trenches is that it makes composting so simple. You don't have to worry about maintaining adequate moisture levels, aerating, or sifting the way you do with a compost pile. Other reasons to give trench composting a try include:
- Trench composting gives plants nutrition right where they need it—at the root zone. Plant roots make their way down deeper into the soil in search of the nutrition you buried there. So, nearby plants are healthier in two ways: They are nourished from the organic matter in the trench, and they benefit from a deep, strong root system. The plants are better able to cope with dry conditions and heat, and they require less babying from the gardener.
- The compost is invisible and does not produce odors. One of the concerns many people have with composting is where to put a compost pile. While there are plenty of small-space composting solutions, trench composting completely eliminates this problem because you bury waste anywhere you have an open space in your garden. Because it's buried under several inches of soil, even the smelliest kitchen waste won't be an issue.
- It's a way to compost even if you're not allowed to compost. Some municipalities and developments have rules against home composting. This is a great way to do it on the sly.
Three Different Methods
You can be as organized or free-form with trench composting as you like. There are three methods you can use in your garden. All three work well, and they work on the premise that you don't want to immediately plant directly on top of composting materials because the area sinks a bit as the material breaks down.
- Trench Rotation. This is a method of incorporating organic matter into a garden a little at a time while maintaining active growing and path areas. You divide the garden into three zones: a trench composting zone, a pathway zone, and a growing zone. Each year, you move the trench compost to a different section of the garden and shift the paths and growing areas as needed. By the end of three years, you've composted under every part of the garden bed, and you can start the rotation over again. If you like order, this is probably the best method for you.
- Trenching Between Rows. Trenching between rows works in any vegetable or annual garden in which the plants are in evenly spaced rows. Plant the crops as usual. In the space between the rows, dig a trench for the compostables. Fill the trench as you add materials, and the compost nourishes the plants nearby.
- Dig and Drop. This is the easiest way to practice trench composting, and it works even in perennial gardens and shrub borders. After you collect a large bowl of vegetable and fruit peelings, take it into the garden, dig a 12-inch deep hole wherever you can find a spot, dump the kitchen waste in, and cover it over. It's fast, it's easy, and it requires very little digging.