Here is a question from Tom:
My big , honkin’ super HUGE , most important and almost life changing question deals with moisture (or LACK thereof). Here in Arizona we have about 6% humidity in the summer . I tried a bin and got it as wet as common sense would allow only to find it drying out at the speed of light by midday . I’m wondering if I can’t set up a soaker hose in one section and keep it REALLY wet while addressing the other areas as the need arises during the day . The reason that it is sooo important is that I’ve read where folks feed and ignore them for days . With the status quo I cannot even leave for a few days for fear of returning to a WHOLE lot of dried crooked sticks interspersed throughout a big box of bedding that crackles to the touch . As much as I don’t want to kill little helpless wiggling souls is the thought of losing good money . Help me PLEASE!!!
You’re in luck – I love “big, honkin’ super HUGE, most important and almost life changing” questions!
Joking aside – you’ve certainly hit upon a really important topic here. It’s not something I’ve really talked all that much about. One reason is that I live in a fairly typical temperate region – i.e. moderate temps with decent levels of humidity during spring/summer/fall (so I’m not really all that familiar with hot, arid environments). I also tend to be a wee bit reserved on this front simply because I don’t want people to end up overdoing it – something that’s very easy to do when using a run-of-the-mill plastic, enclosed worm bin (likely the most common vermicomposting system in use).
You didn’t mention what type of system you are using, but I’m going to assume that it’s NOT a plastic, enclosed bin. While there’s no doubt that this type of bin is great for holding in moisture, this can definitely be a curse in a hot/sunny outdoor location. These systems tend to readily soak up and hold in heat, and have next to no evaporative cooling capacity.
My general recommendations for a hot dry climate would be:
1) Use some sort of wooden bin – preferably partially sunken into the ground (with a decent pit underneath), sitting in a shaded location if at all possible.
2) Maintain a thick layer of bedding materials over the exposed surface of the composting zone at all times. Not sure what materials might be available in a hot dry region (don’t imagine fall leaves, and hay/straw would be all that common – haha), but see what sort of carbon-rich waste materials you can track down (dry grass clippings? etc).
3) Add plenty of slow-release water-rich waste materials. If you freeze fruit/veggie waste ahead of time you’ll have the added benefit of helping to lower temps in the bin (helpful during hot spells).
4) Employ other hydration methods – your soaker-hose idea is great as a back up strategy (if you still can’t manage to maintain moist conditions – or if you are going to be away from home for a few days etc), but even perforated (with really tiny holes) plastic jugs filled with water would likely help a lot, while conserving your water a bit.
5) Make sure you have lots of excellent water-holding materials in the bin – especially in the central zone. If you soak coir bricks and bury them in various locations, for example, every time you add water they should help to wick a lot of it up and then slowly release to the surrounding environment. I suspect that you could even get some good mileage out of old cotton towels, cloths, shirts etc (the added benefit being that it would take a long time for these to disintegrate).
Anyway – just my 2 cents, Tom! Perhaps others will chime in with ideas as well.
Hope that helps a bit!