Harvesting last year’s compost
This is the time to start using your compost in the garden. This month we look at harvesting the well rotted compost at the bottom of a plastic composter. Some of its compost will be ready after a season, but a wooden New Zealand Box with 2 bays takes longer: two years for compostibles to completely rot down. So, if you’re using compost from a New Zealand Box, you’ll need to use the material that has been rotting down for the past two years.

Plastic composters without a hatch
These bins can be hard to get hold of now, but are the simplest and best units to use. Simply lift the bin up and off the heap. This will stay together neatly, it’s like turning out a sandcastle. Put the empty bin beside the heap and fork back into it the material that hasn’t rotted down. By turning the compost over like this, you mix in air and this speeds up the composting process. You then shovel up the finished compost from the bottom of the original heap.
Plastic bins with a hatch
These are now the most widely available bins. You are invited to remove the hatch and shovel up the compost that’s ready. But when you’ve removed some compost, you’ll find that the resulting hole is immediately filled with material that isn’t yet ready for use. You will also find it hard to remove all the compost at the bottom of the bin as your shovel probably won’t reach the far corners. If the bin is no larger
than 330 litres, we recommend removing the bin from its pile as described for a bin without a hatch.
Use the hatch to check how the things are going at the bottom of the bin.
Square or hexagonal plastic bins
These come as flat packs that you’ll have assembled. The sides are held together with long plastic pins
that fit through eyes on the vertical sides. Remove one pin and you can then swing one side like a door.
You fork the uncomposted material to one side and this gives you access to the well rotted compost at the
bottom. Then slip the pin through its retaining eyes and fork back the material you don’t want to use just now. Again this turning will inject air into the heap and speed up the composting process.
A New Zealand Box
This has two bays. You will have filled one with kitchen and garden rubbish in 2006 and covered it with a
wooden or plastic lid. Sheets of cardboard or bubble wrap improve insulation. We no longer recommend
using old carpets as there is some evidence that synthetic chemicals from the carpet can leach into the
compost, thereby contaminating it. Regular turning will have increased temperatures and improved the
quality of the compost. Dig out the compost from this bay. The bay is now cleared for this year’s rubbish!
(A good idea is to turn last year’s half-digested compost by forking it into the empty bay.)

Let your garden enjoy your compost!

See our Organic Gardening section for lots of ways of using your wonderful compost