Harvesting worm castings
Worms compost garden waste and certain table scraps into a rich soil enhancer called worm castings. Harvesting worm castings is necessary to separate the worms from the compost. You know it’s time to harvest worm castings when the soil is dark and there are no visible pieces of uneaten material. For indoor worm bins, this will take about 2 or maybe 3 months. Techniques for harvesting worm castings depends on what type of worm composting you are doing.
Harvesting worm castings from outdoor composting pile
Harvesting worm castings from an outdoor composting pile can be as easy as using a rake to pull back the top layers of compost material. This reveals the darker, richer and organic soil beneath. Use a shovel to dig this out, placing it into a wheelbarrow or onto a plastic sheet. You should see worms trying to hide from the sun. Feel free to pick these worms out and place them back into the composting pile. Or, keep the worms with the worm castings and they’ll make a happy new home in the garden or lawn (or wherever you place the worm castings.
Harvesting worm castings from indoor composting bin
Worm castings are ready for harvest when the soil is dark with no visible plant remains. If your indoor worm bin is a stackable model, most of the worms should have headed up for easier (and tastier) feeding. There will be a few stragglers to deal with.
Remove the lowest bin. There are three techniques from here to separate the worms from the worm castings.
Worm casting harvesting technique 1: place the bin on plastic. Scoop the top layer of worm castings / soil off and place it in a bag or bucket. Exposed to the sun (or light) the worms will dig deeper into the soil. After 10 minutes, scoop off the next layer. Continue this until you have harvested most of the worm castings.
Worm casting harvesting technique 2: place the bin on plastic. Pick around and remove the worms. They are easy to catch. With children, we actually find this one to be the most fun way to separate the worms from the worm castings. (Be gentle!).
Worm casting harvesting technique 3: push the worm castings to one side. Place fresh bedding and food on the other side (covered with a damp newspaper). Let the worms migrate over on their own accord.
Regardless of how you harvest the worm castings, you will end up with a pile of worms to be reused in the composting process (or placed in a garden) and a rich, organic soil enhancer that will make your plants happy and healthier!