This has been our goal – using worms to transform food waste to fertile worm compost. But our above-ground worm bins were just not working. We spent a lot of effort wrapping them in hardware cloth to prevent rodents from nibbling in, but we didn’t have enough worms for the amount of food waste from the kitchen and things had gotten smelly. Not a happy situation!
So, as long as we were going to invest in worms and start all over, we decided to go with the successful in-ground worm bins installed at the Good Cheer Garden, but modify the design slightly to make them rodent (read RAT!) proof. With the advice and encouragement of Todd and Teresa Spratt, we built an in-ground concrete worm bin!
Matt Statz and Hilary Andersen, garden interns, dug the 4 ft wide x 7 ft long x 3 ft deep hole needed to accommodate the concrete blocks.
The bin is set into a hillside, and the hole was dug at an angle. Matt laid the blocks down with a gentle grade so that the lid would be sloping.
Mark Brady simply and brilliantly made the divider with a pallet. The bin has two chambers, which are alternately filled, or finished off and harvested. Worms migrate between the chambers. The lid was built with recycled Trex and metal roofing. Let’s see if any creatures can get in this worm bin!
Todd started the bin up with 9 lbs of worms: 1 lb for every square foot of area. The key to happy worms is bedding, and we have found that horse manure, aged to the point where it is crawling with worms, is ideal. We dump the food scraps into a corner, add the aged horse manure to just cover it, and that’s it. As Todd and Teresa say, “Dump, cover and done!”. In the summer, you may need to also add water, moistening to a freshly rung out sponge. Food scraps can be added every several days depending on how many worms you have, covered, and watered.
Two weeks later one side is half full, and the worms are thriving! So far so good! The Good Cheer Garden in-ground worm bin is working really well, and this one appears to be following in its footsteps. Stay tuned!
October 2011 follow-up: This worm bin rocks! We’ve been getting excellent vermicastings! The only thing we need to watch out for is feeding them less in the winter. Get to know your worms, and adjust for their seasonal variation in appetite. We won a blue ribbon at the Island County Fair for our vermicastings, and the garden sure loves them, too.