Here’s a question from Kevin:
I received as a gift a 5- tray worm farm. i have 2 lbs of
worms. I filled the first tray with coir and potting soil. now i am
ready to start my second tray. what should i put as bedding. i don’t
want to buy potting soil every tray. please give me some advice.
To be totally honest, I’m amazed you’ve been able to keep 2 lb of worms in a single tray with coir and potting soil. I’ll assume you have also been adding food scraps as well.
Potting soil generally isn’t a great material to add to a worm bin – although it is often a lot better than garden soil. This is because it typically consists of mostly peat moss (whereas garden soil has a lot more mineral particles and thus tends to be a lot heavier and more dense, thus impeding air flow in a worm bin).
One of the risks of using commercial potting soil, by the way, is that it can contain inorganic fertilizer salts which can harm or even kill your worms. If it is old stuff that’s been exposed to many waterings (without any fertilizer being added of course), then it should be ok.
Coir can be a decent worm bedding, but it can also be pretty expensive. Aside from that – in my experience, worms don’t exactly love it either. Your best bet with coir is to moisten it well and mix it with food waste (partially decomposed preferably) and let it sit for a bit before introducing the worms.
Ok – now assuming your first tray has gradually filled up over time and it is time to move up to the next tray, the good news is that you definitely do NOT need to use either of the bedding materials you’ve been using. There are even better (free) options in my humble opinion. Shredded newsprint or shredded cardboard (corrugated and/or egg carton cardboard work best) are great choices.
What you will want to do is moisten the new bedding, then mix it with a fair amount of food waste (again, partially-decomposed stuff works best) – perhaps a ratio of 2:1, bedding:food volume. Simply add this material to the new tray then wait. As it decomposes further, the worms should start to move up into that tray – especially if the first tray has little in the way of good food for the worms by that time.
Hope this helps!