During a recent visit to an acquaintance's place, the topic of food waste arose. They lack a secluded spot to establish a compost bin in their garden, and their city collection doesn't offer pickup. They had tried bokashi composting, but with a new baby, they will probably have more than enough to do without caring for a bucket of breaking down organic matter.
However, as they are already used to placing their fermented scraps, it led me to consider on how low-effort and high-impact in-ground composting can be for those without room for a larger system. Trench composting is the straightforward practice of depositing your biodegradable materials – like kitchen scraps, prunings, grass clippings, leaf litter, etc – into a ditch adjacent to where you intend to grow your crops in the future. Over the coming months, this material will gradually break down, fertilizing the soil and bettering its structure, conditioning it to welcome the next season's vegetables. No further effort is necessary from you to engage in this ancient approach.
The technique is easy of putting your compost into a ditch close to where you intend to grow your crops.
You can compost this way in a somewhat shallow trench, though certain guides advise digging down to 60cm prior to placing the materials and backfilling the trough. If you take a more shallow method, it's wise to using a cover with a tarpaulin and pinning it down firmly to stop your beds from being dug up by animals that frequent your garden.
An additional advantage of pit composting is that you can avoid the concern about hitting the correct ratio of wet and dry ingredients. As anyone who has managed a slow or inactive compost pile understands, it can be difficult to find the correct ratio, but trench composting is more lenient. The ideal practice to include a combination of green material and carbon-rich material similar to in a traditional composting setup, but you can be less precise about the ratios.
Being a quite committed practitioner of no-dig growing, I am hesitant about the thought of disturbing the soil alongside or into my veg beds, but I think it's doable to remove a sufficient volume of soil without completely destroying the soil structure. I would consider using this method when renovating a long-term planting area or removing large amounts of perennial weeds, because both involve me to work the soil anyway. Whenever I have to excavate, I'm meticulous to return the earth from where it was unearthed carefully and refrain from working soil when it is very wet.
Pit composting is really worth considering if you're constructing elevated garden beds in your garden, since you can add a base of compostable material prior to completing the bed – no digging required.
