"How hot can my worm composting bin get without killing the red wigglers?"

That is a question I have been getting lately. Worms can actually survive quite high temperatures, but the conditions have to be right. So the answer is complicated, but I think that I can explain to you the problems associated with summer worm bin temperatures and what to do about them. Rest assured that the summer heat will not kill your worms if things are managed properly.

It is my conclusion that it is not the heat itself that kills worms, but instead other conditions that are caused by high temperatures. The primary reason worms might die in the heat is a lack of oxygen. All living things and processes consume oxygen. When food is consumed it takes oxygen to turn it into energy through a process called respiration. Worms are not the only creatures in a bin consuming oxygen but thousands of microscopic life forms as well. So the first thing we should do when the worm bin temperatures start to rise is to reduce the amount of feed going into the worm bin.

So how much and how often do I feed my worms?

The general rule of thumb I use when feeding my worms is well, I don't really have one. It is really simple actually, start with a pound of food for every pound of worms and feed them every 3 or so days. Do this when it is convenient. If it is easy for you to feed them everyday than that is fine as well, just watch that the bin doesn't start to get to much food in it and that no smells emanate. Any smell, mold or flies are signs that there is to much food. It is far better to underfeed than to over feed, especially when it is hot. In the heat cut your feeding in half would be a good starting spot.  Although the worms will not grow as fast they will be healthier.

Moisture and water is necessary in the worm bin but to much can reduce the amount of oxygen available to the worms. This is due to a couple of reasons. The first one seems obvious, the water reduces available air spaces. Just like plants need good drainage so to due worm bins if they are subject to heavy watering. The second reason is a speculation on my part that to much moisture accelerates the consumption of feed and the composting process further increasing oxygen consumption.

So how wet should my worm bedding be? How much and how often do I water my worms?

General rule of thumb is damp enough so that when a handful is squeezed a drop or two of water comes out. You want the bedding to about as moist as a  wrung out sponge. So extra drainage is important when it is hot. You do not want a soaking wet bedding when it is hot. Watering is important when it is hot because it helps cool, but just be sure it drains well.

• Keep the worms in the shade
• Don't overfeed
• Well drained bin
• Screened lid allows for evaporate cooling as opposed to a solid lid

Thanks for reading, now you don't have to sweat the heat (: