A Guide to Composting with Red Wigglers
By Penny Pawl
NAPA VALLEY, Calif. — Hi, my name is Wanda/Willie Red Wiggler Worm (Eisenia fetida) and I live in a worm bin. The bin is cared for by a local garden lover who uses the end product to fertilize her plants.
My bin, where I live with 1,500 to 2,000 relatives, is an old plastic garbage can with half-inch holes drilled all over for air circulation. A lid on top keeps our bedding as damp as a wrung-out sponge, although occasionally water must be added. The bin is kept under trees, so we don’t overheat.
If the bedding gets too wet, we will try to escape. That is why, when it’s raining, you may see some of my relatives on roads trying to find a dry spot.
I really like this living arrangement. Red wigglers eat decaying organic matter, and if we’re not in a bin, we may have to travel far to find food we like. Those of us that don’t live in bins typically live under rocks, pots, leaves and mulch.
A professor at Michigan State University, Mary Appelhof, came up with the idea of using red wigglers to compost kitchen garbage. Her book, “Worms Eat My Garbage,” was published in 1982 and made us very popular.
My name is Wanda/Willie because all worms are hermaphrodites. We can all be mothers if we have a partner to fertilize our eggs. Eggs take about two weeks to hatch, and in only three months, a baby worm can lay eggs and produce its own babies. So, we reproduce quickly. Eight of us can produce 1,500 adults in six months. However, our lifespan is only about one year.
Other types of worms include ground worms that sift soil through their gut and night crawlers who come out at dark and forage. We all contribute to a healthy ecosystem.
We live in the dark because our skin is sensitive to light. If a shovel brings us to the surface, we’ll immediately crawl back under the dirt.
Our keeper was very careful when she built our home. She built it like she was making lasagna, with layers of dried leaves, rice hulls, shredded strips of newsprint, plain cardboard, chicken manure and other organic matter. We particularly like cardboard because we like the glue that holds the layers together. She didn’t even have to remove the tape on the cardboard. We do that for her, and she removes the tape when she harvests our castings (manure). After she made all the layers, she moistened them and covered it with a plastic bag to keep the moisture in. Then we got to work, mixing all the layers as we moved around the bin.
We live on kitchen garbage, but we especially enjoy melons of all kinds. We’ll eat just about anything except dairy products and meat. We like eggshells and love coffee grounds. We don’t eat seeds as they are living and not decaying. Our keeper never puts sick plants or weeds in the bin. Apart from tomato vines, all the remains of the vegetable garden go in the bin and we appreciate that. But if we are fed too much at one time, the bin can get smelly. Not feeding us for a couple of weeks and adding more bedding usually clears up the problem.
Sow bugs sometimes join us in the bin. They eat the same things, and their castings are just as nutritious. We don’t like ants, however. If they move in, our keeper stops feeding us for a couple of weeks and they usually disappear.
We’re happy in the garbage can but other containers work, too. Napa County Master Gardeners and the city and county of Napa give bins, worms and some bedding away at their compost workshops. These are large plastic bins that can be kept in the garage or under a tree.
Every two to three years, our keeper checks the bin to see if we have reduced the contents to compost. If so, she’ll “bait” the bin with mesh bags of food to entice us to move in. Then she can move us to a new bin with new bedding and harvest the contents of the old bin.
Regular compost is a great soil conditioner, but because worm compost includes castings, it has some nutrient value and can be used as a mild fertilizer. Worm castings are sold commercially and are expensive. I have heard the product called “worm gold.”
If you would like to try worm composting or just regular composting, plan to attend the workshop (details below) on Saturday, Sept. 7. Compost bins will be available for purchase and worm bins with bedding and worms will be given away. Sorry, but you must provide the kitchen garbage. Red wiggler worms are available online. One pound of worms is about one thousand.
Composting Workshop: Join UC Master Gardeners of Napa County for a free workshop on “Worm or Backyard Composting: Choose Your Own Adventure” on Saturday, Sept. 7, from 11 a.m. to 1 p.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Learn the basics of hot and cool composting, worm composting and grasscycling. At the conclusion of the workshop, you may purchase a backyard compost bin for $20 (one per household) or get everything you need to build your own worm composting bin, including the worms. Registration required.
Fall Faire: Join the UC Master Gardeners of Napa County for an entertaining and educational event on Saturday, Sept. 28, from 1 p.m. to 4 p.m., outdoors at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Enjoy exhibits on composting, monarch butterflies, succulents, water conservation, bees and more. The program includes activities for kids, a scarecrow contest, giveaways and music. Admission is free.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 a.m. until 1 p.m. at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.
Become a Master Gardener Volunteer: UC Master Gardeners of Napa County is now accepting applications for the Class of 2025. Visit napamg.ucanr.edu to read the informational brochure, then register to attend a mandatory information session for applicants. Application deadline is 5 p.m. on Sept. 25.
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Penny Pawl is a UC Master Gardener of Napa County