Harvesting Vermicompost

From WormWiki

There are quite a few approaches to harvesting vermicompost. Some of the most popular are explained here.

1. Multiple piles - No advanced preparations needed, but takes the longest. a. Dump contents of bin on to a a tarp, separate into multiple piles. b. Wait to allow worms to burrow down in to the piles away from sunlight. c. Remove the tops of the piles. By the time you're done with the last pile, the worms in the first one will have had time to burrow down. d. Repeat until you have a ball of worms at the bottom of each pile and little or no vermicompost.

2. Side to side - Some advanced preparation needed, quicker than #1. a. Move the contents of the bin to one side of the bin and add fresh bedding and food to the other side. b. A month or so later, most of the worms will have moved to the new side where the food is and you can use method #1 to separate those few worms that are left in the 'old' side.

3. Top down - Variation of side to side with a new bin. a. Cut a trash bag open (so it's a single sheet), poke multiple holes with a pen. b. Place trash bag over a new bin that's been prepared a week or so ahead with food and bedding. (It needs to be full of microbes for this to work. c. Dump old bin on top of bag and let sit for a few days. d. The majority of the worms will have burrowed down to the new bin to find food. You can speed up the worm migration by putting the bin in the sunlight. Anything with holes in it can be used, up to and including window screens.

4. Stacking If you haven't bought a stacking system, you can make your own. a. Poke holes in the bottom of your new bin. b. Place it on top of the old bin so that the vermicompost is in contact with the bottom of the new bin. c. Feed only the top bin. d. After a few months, most of the worms will now be in the top bin.

5. Flow through bin (the easiest.) Flow through bins allow you to harvest compost with very few worms from the bottom while continuing to add food and bedding to the top. Check out the worm bag, vermitopia and other flow through options under 'making a bin.'

Other tips.

1. If you've waited long enough, you'll have really good quality vermicompost. If you're impatient (like me), and have waited 3 or 4 months and there's still clumps of undigested bedding, you can put the compost through a large 'sieve.' Get half or quarter inch chicken wire and attach to the bottom of a container that's open on both ends. I folded the bottom of a small box inward to create an open bottom and an open top. Sift the vermicompost through this and replace the bigger bits back in to the bin.

2. If you want to get as many worms as possible to increase your herd and are willing to wait for your vermicompost, let your compost 'mature' for a few weeks. Keep it moist and allow air in (just like the normal bin.) This allows the cocoons to hatch. To remove the babies, one method is to place the compost (or small parts of it) in an airtight container that is mostly sealed. After a number of hours, any worms will move towards the source of oxygen and crawl up the sides of the container. You can also use a ziplock bag with just an inch or so open on one end. You can also use method #1 above.