By: Amy Grant
I think we all know that reducing our contribution to our landfills is imperative. To that end, many people compost in one way or another. What if you don’t have room for a compost pile or your municipality doesn’t have a composting program? Can you dig holes in the garden for food scraps? If so, how do you compost in a hole in the ground?
Yes, and this is actually one of the simplest and most effective methods of composting kitchen scraps. Variously referred to as trench or pit composting in gardens, there are a few different trench composting methods, but it all comes down to composting food scraps in a hole.
Composting food scraps in a hole is definitely not a new technique; it’s probably how your grandparents and great grandparents got rid of kitchen waste. Basically, when pit composting in gardens, you dig a hole 12-16 inches (30-40 cm.) deep – deep enough that you pass the topsoil layer and get down to where the earthworms live, feed and reproduce. Cover the hole with a board or the like so no person or critter falls in.
Earthworms have amazing digestive tracts. Many of the micro-organisms found in their digestive systems are beneficial to plant growth in many ways. The earthworms ingest and excrete organic matter directly into the soil where it will be available for plant life. Also, while the worms are tunneling in and out of the pit, they are creating channels that allow water and air to penetrate the soil, another boon to plants root systems.
There is no turning involved when pit composting in this manner and you can continuously add to the pit as you get more kitchen scraps. Once the pit is filled up, cover it with soil and dig another pit.
To trench compost, dig a trench to a foot or more deep (30-40 cm.) and any length you want, then fill it with around 4 inches (10 cm.) of food scraps and cover the trench with soil. You can choose an area of the garden and let it lie fallow for a year while everything composts, or some gardeners dig a trench around the drip lines of their trees. This last method is great for the trees, as they have a constant supply of nutrients available to their roots from the composting material.
The entire process will depend on what material you are composting and the temperature; it may take a month to compost or as long as a year. The beauty of trench composting is there is no maintenance. Just bury the scraps, cover and wait for nature to take its course.
A variation on this method of composting is called the English System and it requires significantly more garden space, as it involves three trenches plus a path area and a planting area. Basically, this method maintains a three-season rotation of soil incorporation and growing. This is also sometimes referred to as vertical composting. First, divide the garden area into 3-foot wide (just under a meter) rows.
Give this system a few years and your soil will be well structured, nutrient rich and with excellent aeration and water penetration. At that time, the entire area can be planted.
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Trench composting fits perfectly into my crazy gardening life. It’s much simpler than trying to constantly have a pile of cooking compost.
As much as I love gardening there is one aspect that I have always struggled with. And that is composting.
Yes I know I should be doing it! I should be returning as much into my soil every year as I have taken outright!
I also know that composting keeps a bunch of green material out of my local landfill! Again this is great for the environment and something I feel strongly about!
The problem is, I just never seem to get around to it. I’ve had nice compost bins at all of our other places (this is our 3rd home) but I just haven’t been able to settle on a spot here at our new house. And even when we had a compost bin I just never seemed to get it right, how much green material, how much brown, when to turn it, do I need to water the pile, it is “hot” enough. Urgh!!
Now don’t get me wrong, I know the value of a compost pile. I know I should be doing one and I’m sure I will get back to it someday soon. But right now building a new compost bin is just not on the radar!!
So what do I do with all the excess, lawn clippings, leaves and food scraps coming out of our garden? I simply take care of them by trench composting.
Now I have a compost heap, but it looks unsightly, could attract vermin, takes up a lot of space and hasn’t given me any useable compost. Plus I am limited with what kitchen waste can go on there. That’s mainly because I have forgotten to turn it. If I had turned it I might have attracted newts and slowworms, but still probably also the hairy mammals with nearly hairless tails. I’m just not good at tending to compost and neither my garden or the amphibians were benefiting. I’m clearly not that keen on the double handling! Though to give some credit a potato plant had established itself on the edge of my heap. It meant that still lots of food waste was being disposed of in my dustbin and being taken off to landfill. When household waste festers in black bins bags in landfill site, undergoing anaerobic fermentation creating lots of methane – one of the causes of global warming. With the trench or pit composting method, the air in the soil gives support to aerobic microbes which do not create methane.
A variation on this theme is to use holes instead of a trench. The holes can be dug between plants all season and extras dug in late fall and covered with a handful of straw. Use a trowel, augur or post-hole digger, depending on your circumstances.
Superb! But since I am lazy, I will use this as well as my barrel. The barrel, I just go out, open lid, throw in. No digging til I am ready to garden. Hopefully next year will be gardening time.
Since I have a very small backyard and an even smaller garden 3x4, I love trench composting. I have noticed that when I bury my scraps they are completely gone in a maximum of two weeks. Any remarks as to why the ground absorbs the scraps so quickly? This garden is less than 1 year old. I bought a pound of worms and they hung around for about a month and now are gone. I have lived in the AZ desert all my life but have never seen anything like this.
The more bacteria, and enough water (but not too much!) does the trick. It sounds like you have the right ingredients for a very active compost pile, congrats!
Would you happen to know why the worms are not wanting to stay around?
I was wondering that myself when I read your comment. My guess is they prefer to spread out a bit, but I really don’t know. If you create the right conditions (food, enough water, but not too much) they will repopulate the area.
from what i understand, fishy scraps are no good for composting (shrimp shells, fish bones and skin, etc.)-- bad bacteria and stinky. is this true for trench composting too?
I put just about everything in the trench, including some traditional compost "no no's" like meat, bones, cheese and bread. Fish isn't a problem as long as you bury it deep!
The fish do make a good fertilizer but do smell. They are best used at the bottom of a hole covered with a good amount of dirt. The roots will find them and the animals usually won't bother with them if they are far down enough to cover the smell. We lived on a lake that depleted with oxygen every winter. The shores where lined with dead fish every Spring. We would dig deep trenches and pour fish in and cover them then plant the garden on top. The soil eventually became very rich, as the fish from the year before which had decayed and lost its smell, mixed with the soil while digging the next year.
i agree with you! why bother with the expense, all that turning. i just toss my table scraps under the bushes. i however avoid paper that has been bleached with chlorine. brown coffee filters ok, but i'd rather save them for biodegradable peat pots :)
Why bother with all that turning? Aerobic decomposition vs anaerobic.
Thank you for bringing simplicity back. I also remember my grandma using this method, she was also raising goats, sheep and rabbits and was adding the manure to a separate pile that was left to mature in sections.
Thank you so much for your instructable. I am very excited to start my own compost trench, and delighted to learn i don't have to buy , build or till any gadget to compost.
most newspapers are ok the ink is soy most of the time
hey Meddler- don't be so hard on the wifey!It was worth it! I've got one of those black tumblers, <$120>and their great! It also has a catch basin which I make compost tea with. I also have a 4 part pallet compost system,and plans to start another. This way there's always compost going, and I need alot. Even if you didn't have any compost at all, just mix some grass clippings from the mower- organic fertilizer in the garden, and I know you'll get produce. Then start incorporating the kitchen scraps into the garden as the season goes along. And remember you dont even have to dig to build a small garden if you don't want to just lay newspapers down- wet real good,secure with rocks if windy, and plant on top of that..no tilling.
this is a wonderful instructable! thank you. my grandmother never composted - she buried all the kitchen scraps in her garden. she had quite a large plot of beautiful vegetables and flowers, so i know this method works!
i'm reduced to "composting" on a second floor balcony at the moment--So, into a large terracotta (in this case plastic) pot -I'm in the north, and don't want it to crack- I put all my good vegetable and fruit ends, after blending them to mush with a stick blender. I pour this onto a base of decent earth (in the pot) and work it in with my hands. It smells divine and fresh, and feels good, like really good soil. Next spring, it'll go into the ground. thanks for the nod to green manure crops. any specific suggested reading?
IMHO that's too much work. I layer a few sheets of newspaper under a thick layer of grass clippings between my plants to prevent weeds from growing. Everyday I put the my compostables in a plastic container with a lid. It's normally a smaller amount, between 1-4 cups. Once a day I pick a spot under the grass clippings (a different spot each time) and shove the compostables under it. That's it. It starts to decompose immedietly giving the plants nutrients that year and the next year, when I barely till it, it's pretty much dissolved into the soil. Newspaper shreddings and some peels (canteloupe for example) take a while longer to decompose but not softer vegie parts (like tomato).
Oops, forgot to say that I took the compostables out of the plastic container first. This plastic container is NOT compostable. unfortunately.
If your going to use newspaper the black and white part is ok most printers now use soy based ink, you dont want to use the color section that ink is still toxic.