Wheelbarrow next to compost heap.

How long does it take to make compost?

The process of making compost can take anything from a couple of weeks to several years – it all depends on which composting process you use, and how much work you put into it.

Let’s dig into the details…

Compost in two weeks

One of the fastest ways to make compost is to use the Berkeley method, which promises compost in 2-3 weeks. (While 2 weeks is just 14 days, most followers of the Berkeley method estimate it takes around 18 days – which is still exceedingly quick.)

A summarised version of the process is below:

  • Chop up material into small pieces.
  • Build the compost heap in 1 to 2 days.
  • Ensure that the pile has a carbon:nitrogen ratio of roughly 1:30.
  • Ensure the moisture level is about 50%.
  • Build a pile of at least 36″ x 36″ x 36″, using bins if possible.
  • The pile needs to be turned every day to reach a finished stage within two weeks (or slightly longer). Turning it every other day will add a week to the composting process. In most circumstances, nothing further is added to the compost heap during this process.

For more information, see Rapid Composting by Robert D. Raabe.

Despite its speed, there are a number of disadvantages with this system. Most people do not have enough compost material to build a large compost pile in one go – and most gardeners have a constant supply of material which needs composting on a regular basis. Building a whole pile in one go is not realistic for the average gardener. What’s more, there’s some serious work involved in turning compost daily (or even every other day.)

Compost Bins

Insulated bins such as the HotBin compost bin or the Green Johanna are a great alternative to compost piles. HotBin estimate that rough compost can be made in four weeks, while finer compost can be made in about three months.

Compost tumblers are designed to aerate the compost in order to speed up the decomposition process. One study by Which Magazine found that they took around ten weeks – four weeks longer than convention bins which were regularly forked over.

Cold composting

At the other end of the scale from the Berkely method is cold composting. Cold composting is probably what most gardeners do, and can involve just slowly adding to a pile of material in a garden. Moisture, the size of the compost heap, the fact it is built slowly and the lack of the correct carbon:nitrogen ratio generally mean these compost heaps do not heat up.

Cold composting generally takes around a year, although some people prefer to leave it for two years.

Maturing Compost

Unfortunately, while compost that is no longer hot is sometimes considered to be “finished compost,” the results are not always that great. Allowing the compost to mature helps to further remove acids and pathogens, and allows worms to work their magic, digesting their own body weight in compost every day.

Every composter has their own preference for this stage, which can vary from a few weeks to several months. In general, the longer the compost is left the better the quality will be.

Speeding the process up

All methods of composting require patience. However, if you do want your compost faster, check out these 16 ways to increase the speed composting speed.

Photo credit: Tiffany Woods