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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

Feeding the worms. © Robert Queen

December 1998


A four-syllable word for the care and feeding of your worms.

Maureen Mecozzi

Feeding the worms. © Robert Queen

Time to eat | Worm watching | The harvest | How to harvest
Composter's Corner: Mary Ann Swenski

You've got it all – the bin, the bedding, the worms, the waste. You are ready to become a vermiculturalist, someone with the high calling of raising worms for the great benefits they bestow upon humanity.

After selecting a good site for the bin, prepare the bedding. Figure on five to eight pounds of bedding for a 2'x2' box; nine to 13 pounds for a 2'x3' box. Place the bedding in a clean trashcan, plastic leaf bag or other large container. Pour in three pounds of water per pound of dry bedding, and mix well. (For reference, remember that a pint of water weighs one pound. A gallon of water weighs eight pounds. If you were using eight pounds of bedding, you'd need 24 pounds of water, or about three gallons.)

The bedding should be uniformly damp, but not dripping wet. Toss in a handful of soil, crushed eggshells, or other additives. Lift and fluff the bedding to aerate, then put it into the bin.

Sprinkle the worms over the surface of the bedding, gently untwining any wiggling clumps. Turn on a bright overhead light and the worms will burrow down into the bedding. It's a good idea to leave a light on your worm box for the first three or four days. Worms that have been transported through the mail or in a vehicle may want to escape initially following the bumpy ride. After a few days, they settle down and will stay put.

Time to eat

Now you can feed your new charges. Mentally divide your bin into four or more sections and attach a sequential number to each. Bury scraps under a few inches of bedding in the first section. Cover the bin with a wooden or plastic top left slightly ajar, or with a piece of loose black plastic, or with two or three newspapers. Turn out the light. And take satisfaction in knowing those worms are working hard for you.

The next time you're ready to feed your worms – four or five days later, perhaps – bury the waste under the bedding in the second section. The time after that, bury it in the third second. And so on. By following a rotation, you won't have to dig into waste that's not yet "finished."

Some people keep a covered "holding bin" in the refrigerator or under the kitchen sink to keep scraps until enough have accumulated to give the worms a decent feed. Other vermiculturalists add scraps to the worm bin right away, every day. It's your call.

Voracious appetites they may have, but redworms can only eat so much. If your bin starts to smell, you've added too much food for the worms to consume at a reasonable, aerobic pace. Give the bedding a stir to aerate, cover the box, and add no more scraps until the odor is gone.

When you expect to have lots of food scraps – in late summer during canning season, or over the holidays – plan to set up a interim bin, or use another method to dispose of food waste.

Worms are low-maintenance, not no-maintenance. You can skip two or three weeks without feeding them, and no harm will be done. Any longer than that, and you'll have a big box of dead worms. What's your preference?

Worm watching

Think of it: thousands of worms relying upon you for their every need. It's a heady responsibility demanding careful powers of observation. When you see worms scaling the walls of the bin in a desperate effort to escape, or when the bin population goes into decline, it's time to make some adjustments.

Worms climbing up the container sides could mean the bin is too hot. Shade the box or move it to a cooler location. The bin also could be too wet. First, try leaving the lid ajar about an inch. If that doesn't work, add fresh bedding and more ventilation holes. If the bedding seems dry, sprinkle it with water until it's damp like a wrung-out sponge. If the bedding has a salty or acidic smell, it's best to change it.

Though worm-watching is not about to replace whale-watching on the popularity scale (yet), it is an intriguing way to witness nature at work up close, and a great way to introduce children to ecological concepts. Mind your worms, tend to their simple but vital needs, and you will be amply rewarded.

The harvest

A few months pass, the worms are thriving, and you are absolutely thrilled because you are no longer sending food waste to the landfill. Be proud. Take a bow. Flip that potato peel into the worm bin.

Now your true interest in vermiculture must come to the fore. The products of worm cultivation depend on the three methods of harvest.

  1. If you want worms primarily for fishing (and how could you, when they have been slaving away for you?) harvest the worm castings every two to three months and move the worms to fresh bedding. May you never reach your limit again! Follow harvest method #1, and you'll end up with less compost and more worms.
  2. If you practice vermiculture solely to produce compost, bury food scraps for four months. Then leave the bin alone for another three or four months. You will have committed vermicide: All the worms will be long dead, but they will have bequeathed to you a box full of nice black vermicompost. Try to contain your glee.
  3. If it's worms and compost you're after, harvest the castings every three to four months and move the worms to fresh bedding. Or help a freind get started composting. As long as you keep feeding them, the worms will keep on casting!

How to harvest

The methods of bringing in the harvest are as varied as vermiculturalists themselves. Just remember that worms move away from light, and from extremes in moisture and temperature. They move toward a source of fresh food. These guidelines will help you devise an individual harvesting technique to separate worms from compost. If you're not feeling creative, here are two guaranteed harvesting methods:

The Dump and Hand Sort – Place a large sheet of plastic on the floor or on a table. Don your rubber gloves. Dump the entire contents of the bin onto the sheet. Shape the compost into cone-shaped mounds. Shine a bright light above the mounds; this will drive the worms toward the bottom interior of each mound. Wait 5-10 minutes, then gently scrape off the layers of vermicompost until all you have left is worms. (You may see tiny, lemon-shaped cocoons; these contain baby worms, so be sure to add them to the new bin.)

Harvesting vermicompost. © Mary Appelhof

Put the worms into a temporary storage container while you clean out the bin and fill it with fresh bedding.

If you use a wooden box, you can prolong its usefulness by rinsing it out and letting it dry first before adding bedding and worms.

Dumping: the first step in sorting worms from compost.

© Robert Queen
Dumping: the first step in sorting worms from compost. © Robert Queen

Divide and Harvest – Shift all the old bedding, castings and worms in the bin to one side. Add fresh bedding to the other side. Bury fresh scraps in the new bedding for a few weeks, and keep the new bedding covered. Leave the old bedding uncovered. Check after a week or two; the worms will have migrated to the fresh bedding. Harvest the vermicompost, then fill the empty side with fresh bedding.

Composter's corner: Mary Ann Swenski

Life-long gardener Mary Ann Swenski pursues her avocation with a passion. She's the founding member of The Gardening Angels, a local garden club in Iron Mountain, Mich., has received training as a Master Gardener and Master Composter through the University of Wisconsin Extension, and teaches vermicomposting in schools, to Scout troops and other groups. She's easy to recognize: Just look for the lady with the worm on her hat!

"I had my first bin 'up and running' in June, 1997," says Mary Ann. At a local hardware store she purchased a 20"x14"x9" covered plastic container and drilled 18 drainage holes in the bottom to make the bin. After burying about nine pounds of scraps per month in shredded paper bedding, Mary Ann harvested her first castings in December 1997.

"I keep my bin in the basement laundry room, where it's approximately 60-62 F," she says. "It's up on small blocks to provide air circulation. There is NO odor!"

Mary Ann uses a hand cultivator tool to lift the bedding and add scraps. "I sometimes go into the bin and just turn things over so the bedding doesn't settle too much," she says. 'The aeration is helpful." She adds scraps a couple of times a week, storing the scraps in a plastic container until it's time to feed the worms. "My married daughter can't believe I'm willing to keep a 'compost pail' in my kitchen!" she laughs.

From experience, Mary Ann avoids putting potato peels and uneaten tomatoes in her worm bin. "The potatoes tend to sprout, and I don't like having those long, stringy sprouts in there," she says. "The tomatoes didn't pose a problem until I used my castings to top-dress all my flowers in pots, indoors and outside. Soon I had volunteer tomato plants popping up all the time." Screening the vermicompost helps remove seeds.

"I think anyone who has an interest in gardening and the environment should also have an interest in vermicomposting," says Mary Ann. "Whatever each of us can do to give Mother Nature a helping hand can do good things for everyone's future on this wonderful earth!"