Harvesting Your Worm Castings

It’s Time to Get Sifty!

Freshly sifted worm castings.

    It’s been a few months since you’ve started your worm farm. You notice your population starting to increase, the amount of food they’re eating has started to grow and the bins are feeling pretty heavy when you’re checking on them. You can really see the worm castings that are taking over their homes. It may be time for you to sift! 

    Since the worm castings have a lot of living microbes and good bacteria that plants love, it’s best to wait and sift until you know you’re going to use it. If you have multiple worm farms, it may be best to sift one farm when you’re getting ready to start seeds, since vermicompost makes a great seed starter while saving the other farms for when you want to mix into your soil or add directly to your plants. 

    The vermicompost may be pretty wet when you want to sift, so it helps to stop feeding about two weeks to a month before you’re ready. Make sure you add in some extra bedding as well to help absorb the excess moisture. 

Mining for Your Black Gold

Now that your farms are ready to sift, you want to make sure you have everything you need. There are tons of different ways to sift your compost out, and you may find that our ways don’t necessarily work best for you, and that’s alright! You can hand sift, you can use an electric sifter or some people are crafty enough to make a hand-cranking sifter. Right now we have to hand sift, so we’ll be talking about the different things you’ll need to accomplish that. 
    We have two types of sifters that we use at Sevans Wormery. We have a preliminary sifter that we use to separate out pieces that haven’t been completely composted by the worms yet, so that gets set aside to add back into your farms. We also use this first sift to pick out any straggler worms. The second sifter is what gets us the fine, soil-like consistency. Pro tip: looking to make compost tea? Use your rough sift to save time and energy! It makes tea that is just as effective, but with less hassle for you.

Our first round sifter is on the bottom and our fine sifter is on top.

    To make a sifter, all you need is some 2x4s, some screws, a fine, mesh screen (like the ones on a screen door) and 1x1 wiring if you want to make both kinds of sifters. The sifters work best if you have longer side boards that act as a handle, and it’s definitely easier to do with a partner. We find that sifting over a wheel barrel works best for us, so we made a sifter that fits over that. As long as you’re able to separate out your bedding from the vermicompost, it doesn’t really matter how you do it. Luckily the worms are very easy going!