Trench Composting in the Vegetable Garden

Gardeners are aware of the nutritional value and the structural benefits that compost has on garden soil. However, some gardeners may not have the time or space to build a traditional compost pile. Trench composting is one of the easiest and most hands-off composting methods a gardener can use.

Commercial farmers have been practicing a larger scale version of trench or pit composting technique for years. They dig deep underground furrows to hold large amounts of organic waste such as hay and manure – both of which are abundant on many large operating farms. Backyard gardeners and composters can adopt this style on a much smaller scale.

There’s no bin to make or purchase and no need to think about the right balance of greens and browns. There’s literally no turning, aerating, or wondering. Eventually, the organic materials will decompose and turn into compost, automatically adding nutrients to garden soil.

How to Trench Compost

Trench or pit composting is cold composting in its simplest form. This composting practice is as elementary as it gets. The gardener digs a trench or hole between 1 and 2 feet deep anywhere in the yard or garden. Then organic waste is placed inside the trench or pit, covered up, and then left alone.

Organic Materials for Trench Composting:

Below are examples of organic matter that can be used for trench composting. By no mean is it exhaustive. Most materials used for traditional piles can be used for trench composting.

• Kitchen waste such as fruit and veggie peelings, tea bags, coffee grounds and filters, egg shells, etc.
• Spent flower heads, pulled weeds (before they develop seed heads), old fallen or destroyed fruits and vegetables.
• Grass clippings
• Perennial plant trimmings
• Rabbit manure

*Chicken manure shouldn’t be used for trench composting as it could get too close to plants. Chicken manure should be placed into a traditional compost pile. Also, dog and cat poop should never be buried in a vegetable garden bed.

The depth of the trench is determined by just how much organic material the gardener wants to bury at the time. This type of simple pit composting becomes especially handy while deadheading flowers or removing spent or fallen fruits and veggies in the garden or yard. Trench composting also saves time and energy from walking to and from the compost pile for just a couple of spent flower heads.

Traditional compost pile maintenance is unnecessary because the waste is buried into the ground; it actually stays warmer during the cold months and holds moisture longer during the warm months. The decomposers are immediately drawn to the organic matter and turn the waste into a nutritional smorgasboard for plants.

A variation on this theme is for the gardener to dig a long trench right in front of vegetables – one row at a time. Spent plants, ruined veggies, kitchen waste, and other compostable goodies can be tossed into the trench and then covered up. The resulting compost works as a side-dressing of nutrients for the plants.

Alternate Trench Composting Method

Similarly, if there are footpaths between rows of vegetables, a trench may be dug right down the middle of the footpath. The organic matter can be buried in the trench and then covered back up with soil. A cover such as straw, grass clippings, cardboard, etc. can be placed over the soil for a firm footing so the gardener can continue to use the path.

If the foot path trenches were started in the early spring or beginning of summer, the next spring the gardener should be able to uncover the trench and toss the new compost onto the garden bed. In time, the entire vegetable garden bed will be transformed with excellent soil and nutrients.

Interested in reading more about composting? Check out How Worms Improve Soil in the Vegetable Garden and What Compost Does for the Vegetable Garden.