Your vermicompost will be ready to harvest in as little as 3-6 months. Your vermicompost is ready when it is dark and crumbly, and none of the original bedding or food scraps are visible. You will also notice that the volume of the bedding has reduced.
Harvest your vermicompost on a regular basis. If left too long, finished compost can become toxic to the worms.
Harvesting Method One: Harvest by Hand
This method is the most labour intensive, but allows you to keep as many worms and worm cocoons in your vermicompost bin as possible. The whole process should take about 2 to 3 hours.
1. Under a bright light, empty the contents of the bin onto a large plastic sheet, such as a table cloth or flattened garbage bag (this can be done indoors or out).
2. Divide the vermicompost into about eight piles and form each pile into a pyramid shape. Let the pyramids sit for about 15 minutes, allowing the worms to naturally move away from the light and down into the bottom of the pyramids.
While you wait for the worms to move to the bottom of the pyramids, take the opportunity to mix up a fresh batch of bedding and add it to the empty bin.
3. Starting with the first pyramid, use your hands to scrape a layer of vermicompost from the bottom edges, sides, and top of the pyramid. Place the collected vermicompost in a separate container.
4. Continue scraping vermicompost from along the bottom, sides, and top of the first pyramid (removing stray worms and placing them in the fresh bedding as you go) until you begin to see a large number of worms. Reshape the pile into a pyramid and move on to the next.
Despite your best efforts, some worms and worm cocoons will get harvested with the finished vermicompost. That’s ok!
5. Continue this process until you have harvested and reformed each pyramid. By the time you get back to the first pyramid, the worms will have moved closer to the bottom and you can begin scraping compost up along the sides and top of the pyramids again.
6. Continue working on each pyramid (you may have to go through the cycle 3 to 5 times) until all you are left with are eight small piles of mostly worms and a small amount of the original vermicompost. Place the worms and remaining vermicompost in the bin with the fresh bedding.
7. Store the harvested vermicompost in a cool, dark place until you are ready to use it.
Harvesting Method Two: Divide and Harvest
This method is simpler than the first, but you will retain fewer worms and worm cocoons in your bin. Not to worry, the worms in the bin will continue to reproduce and the harvested worms and cocoons will be beneficial to the soil when you use the finished vermicompost.
- In a separate container, mix up a fresh batch of moistened bedding.
- Push all of the finished vermicompost (and worms) to one half of the vermicompost bin. There should be enough space, as the original bedding has reduced in volume.
- Fill the other half of the bin with half of the fresh bedding mixture. Place your next feeding in the fresh bedding. Continue rotating your feedings as usual on the fresh side of the bin.
- After about 4-8 weeks, most of the worms will have migrated over to the fresh bedding. Remove the finished vermicompost and replace it with the remaining half of the fresh batch of bedding.
- Store the harvested vermicompost in a cool, dark place until you are ready to use it.
Uses for Harvested Vermicompost
It’s time to complete the cycle by using the vermicompost to help your plants and garden grow.
Finished vermicompost is a combination of worm castings and decomposed organic material, as well as worms, worm cocoons, and other decomposer organisms.
- Top-dress houseplants or mix half-and-half with potting soil – the vermicompost will perk up your plants by adding nutrients to the soil, and provide great water retention, especially during the dry winter months.
- Top-dress flower or vegetable garden beds, or place in seed rows or holes dug for transplants – vermicompost is completely natural and non-burning, so it’s safe to add directly to your plants and garden.
- Mix half-and-half with soil and/or peat moss to germinate new seeds for a flower, herb, or vegetable garden – vermicompost provides a quick source of nutrients to plants and also retains nutrients in the soil for future use.
- Fill large glass jars and give as gifts to friends and family – dress up the jar lids with a piece of fabric and ribbon, and include ideas for use on house or garden plants.