DEAR GARDEN COACH: I live in a condominium with a small patio where I garden. I don’t have a place for a compost pile, but am thinking about a worm bin. Can you advise on the best way to get one started and how to care for it?
R. Fong, Bay AreaDEAR R: Worm bins are self contained and easy to maintain. However, they are a bit different from a compost pile where you add materials from your garden as you maintain it. Worm bins use kitchen waste.
I have been vermicomposting for about 25 years. I have the same box that I started as a project with my daughter when she was in third grade. Each spring I harvest the castings to use as a top dressing for my container plants and they love it.
Red wigglers (Eisenia foetida) are used in worm bins. They love a warm habitat, ideally between 55 and 77 degrees. You want to make sure that your bin is placed in a shady, sheltered area where it won’t cook or freeze.
These are different from earthworms that like cooler temperatures. Red wigglers like darkness and are surface feeders so a depth of 8 to 12 inches is sufficient for your box. Overall size does not matter.
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The container needs to be dark, not clear, and holes should be drilled on the bottom, sides and top; worms need air just like we do. There are many types of commercial worm bins available, but I cannot comment on these because I have not used them.
There are three layers to your bin: bedding material, food scraps and worms, and additional shredded newspaper on top of the food.
The bedding material can be shredded newspaper or I like to use decaying oak leaves. Fill the box about two-thirds with the bedding material and moisten; add the worms and food, and top with moistened, shredded newspaper.
It is important to bury the food each time you feed the worms to avoid attracting flies. The worms will eat the newspapers so you will have to replenish as it disappears.
Determining how many worms you need and getting the box started is probably the trickiest part. A pound of red worms will eat about a half-pound of food a day. My recommendation when beginning a bin is to buy a pound of worms and feed them about a half pound of food. A large yogurt container is a good measuring cup.
Do not feed the worms again until they have eaten that food. Eventually, as the worms reproduce, you will be feeding them more often.
Worms are vegetarians and are not fans of junk food. Limit the amount of citrus, which can kill them with too much acidity.
It takes about 6 weeks to see a change in the box. You will begin to notice the castings, which are the nutrient-rich humus that is created by the worms waste. Your bin should never smell like garbage, but more like a forest floor.
I harvest my castings each spring by placing the food on one side of the bin; worms migrate to where the food is and then I can collect from the other side. The castings are never worm-free, but I use them in my potting mix or on plants where they will continue to help aerate the soil and feed my container planting.
One of the best books that is still published on vermicomposting is “Worms Eat My Garbage” ( Worm Woman Inc., $12.95) by Mary Appelhof.
Published at Thu, 30 Mar 2017 21:00:48 +0000