Something I get asked periodically is whether or not a compost tumbler can be used for vermicomposting. The answer to that question is YES…and NO!
NO, I definitely wouldn’t recommend using a tumbler as an actual worm bin – even if you were able to keep temps cool enough to avoid killing the worms, and could resist the urge to turning it all the time – but YES, a tumbler can be a really helpful vermicomposting tool – specifically, for helping us Worm-Heads to create some really nice “worm food”. This is exactly what I intend to start doing fairly soon.
Some time ago I mentioned my plans to build some sort of DIY compost tumbler. Well, let’s just say it’s been a pretty busy spring, so the project (among others) ended up getting side-lined a wee bit! The good news, though, is that thanks to my dad’s ongoing help, the tumbler is very close to being ready for action!
So why/how is a compost tumbler good for making “worm food”?
Tumbling waste materials is a great way to mix them up and allow them to go through an initial “pre-composting” phase prior to feeding them to your worms. Worms love moist, microbe-rich foods so they are much more likely to move into (and quickly process) pre-composted wastes vs those simply added directly to the system. In larger worm beds (where more material is added at once) pre-composting can also be important since there will be less potential for overheating.
A big part of my focus early on will likely center on various mixes with coffee grounds. I’ve been pretty happy with the way the worms have responded to the grounds in my beds this year (as compared to previous years), but I suspect I can make this material even more appealing if I pre-compost it with some other wastes (cardboard etc) beforehand.
Anyway – I will certainly keep everyone posted!