Composting FAQ

Short answers to the questions that come up most. Each links to the longer version if you want the reasoning. Below: the practical detail on composting questions, and what most guides leave out.

A notebook and pencil on the edge of a compost bin, representing common composting questions — Composting questions, answered as briefly as they deserve.

Does compost need to be turned?

No. Turning speeds it up and keeps it aerobic; a pile you never touch still becomes compost, just slower. See cold composting.

Why is my pile not hot?

Usually too small, too dry, or too short of nitrogen. A pile under about a cubic metre struggles to retain heat at all. Full answer at compost not heating up.

Can I compost in winter?

You can keep adding all winter. It will not do much until spring. See winter composting.

Do I need a compost activator?

No. In a pile with adequate nitrogen the microbes arrive on their own. They are already on everything you put in.

How do I know when it is done?

Dark, crumbly, smells earthy, and you cannot tell what it used to be. See using your compost.

Will it attract rats?

It can, particularly with cooked food, meat or dairy. Mostly preventable, see rats in compost.

Is compost the same as fertiliser?

No. Compost improves soil structure and feeds soil life; its nutrient content is real but low and slow. It is a conditioner that happens to fertilise.

Answers to the rest of the questions

Composting 101 is the longer form of this page. The four things that matter, how to build a pile, and what to do when it misbehaves. Free PDF, 14 pages.