A little while back, a very good friend of mine approached me with a simple question:
What compost bin should he choose for their household?
While it’s a simple question to ask, there are many possible “right” answers, depending on the circumstances.
This post outlines a few of the options, and explores how the decision was made.
The situation at hand
- Classic two-parent, two-kid family, with both kids still quite young.
- Located in inner-west Sydney, living in a free-standing house on a fair-sized block of land.
- Due to the demands of the kids, there is no time for either adult to garden, beyond a few pots of hardy herbs.
- Existing ornamental garden beds and a number of trees, as well as areas of grass.
- A single lemon tree of some age, not well fed and producing few lemons.
- A general interest in “saving the environment”, but are pragmatic about what they realistically have time for.
So, what composting solution would fit?
Option 1: full-sized compost bin
The classic composting solution is, well, a compost bin. The idea is simple enough: you put a mix of “green” and “brown” material into the bin, keep it moist, and give it time. In due course, it decomposes down to rich compost that can be used in the garden.
There are many options, from fancy (and expensive) Aerobins, all the way down to simple one-piece bins with a lid. The advantage of fancier options is typically two-fold: they claim to decompose the scraps quicker, and they typically give easier access to the compost without having to wait for the whole bin to compost down.
One of the challenges for compost bins, however, is that they work best when full. Ideally, “hot composting” involves at least a cubic metre of material, making it less suitable to top-up-as-you-go situations.
And in this situation, there is the one big problem: what to do with the compost?
It’s all very well to be creating lovely compost, but without a vege patch, what’s it needed for? The decorative garden beds would benefit from the compost, but not to the extent that you’d go to the year-long effort of running a compost bin.
Option 2: worm farm
On the surface, worm farms are very similar to compost bins, but they work on quite different principles. Instead of composting via bacterial processes, worm farms use … worms … to break down scraps.
The worms are regularly fed of things such as kitchen scraps, which they munch through to create vermicast (worm castings) and “worm tea” (liquid fertiliser). This is truly wonderful stuff, which plants love.
There are an incredible range of worm farms of every size and shape, each suited to a different circumstance. Worm farms thrive on small, regular feeds which is a good match for a household’s worth of kitchen scraps.
Care, however, needs to be taken about what goes into the worm farm (no citrus or onion, for example). And again the big problem: what to do with the output of the worm farm?
Option 3: in-ground composting
The last option considered was an “in-ground composting”. This comes in many forms, from the “Little Rotter” compost bin shown above, through to a simple length of pipe embedded into the ground (the favourite approach of permaculture folks).
In all cases, the principle is the same. Drop kitchen scraps into a container that’s embedded into the ground and open at the bottom. The worms that naturally live in the garden are attracted to the scraps, which they munch through. The nutrients then leach into the surrounding soil.
(My grandma still uses the simplest version of this approach: dig a small hole in the ground, drop in the scraps, cover it back over with soil. Her vege patch results speak for themselves!)
In the end, the in-ground composting was the chosen option.
The lemon tree was the key: by placing a number of in-ground compost bins around the drip line of the tree, kitchen scraps could find a better purpose, and the lemon tree would thrive as a result. With the in-ground option, there was also no upkeep or pressure, and it’s well suited to regular small feeds.
Your mileage will vary
In all cases, the natural processes of composting work best when they’re in sync with the human processes of the household. And bigger (and more complex) isn’t necessarily better!
So there isn’t one right solution, only the solution that best fits the circumstances.