The compost must be moist to allow the micro-organisms to develop because they need water. The ideal humidity level is around 50-60%. But it is not necessary to buy instruments to measure this rate precisely. You will learn to recognize a compost that is too wet or too dry simply by observing the few simple signs presented in this article.
Moisture Level Indicators
To start, you can do the fist test: take a handful of compost in your hand and squeeze it shut. When you open your hand, the compost should stay in shape, while gradually coming apart. If it stays together, it is too wet. If it crumbles immediately, it is too dry.
The presence of sowbugs or ants can also indicate low humidity, as can the appearance of white spots. On the other hand, a compacted, smelly compost is a sign that the humidity level is too high. In this case, it’s not composting, it’s rotting.
To remedy high moisture content, add wood shavings to absorb the moisture. The moisture is mainly provided by nitrogenous compounds (spoiled fruits and vegetables, peelings). You can also stir it to aerate it.
If it is too dry, bring less dry matter (wood chips, dead leaves…). And if the problem is recurrent, move the composter to a shadier or less windy place if you can. You can also open the lid when it rains, but do not water it! In our regions, it is easy to regulate the humidity of the compost without wasting drinking water.
In any case, do not be alarmed if the humidity level of your compost is not constant. It is quite normal for compost to be drier in the summer and this will have no other consequence than to slow down the composting process a little.