Composting With Worms

More worm composting information

Introduction

Part 1:
Worm box basics

Part 2:
Worm box management

Part 3:
Commonly asked questions

More worm composting information

Composting coffee grounds

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Once people raised worms only as bait for fishing. I have never speared one of my worms with a fish hook, but I wouldn't want to be without a worm bin. Provided with food scraps from my kitchen and some recycled newspaper, the worms make beautiful, rich compost for my garden.

Worms eat fruit and vegetable scraps, coffee grounds and tea leaves (filter and bags go in, too), grains, pasta, and breads that aren't "polluted." Worm bin pollutants include oils and animal products: meat, fish, butter, cheese, and sauces.

Too often these organic wastes are sent out with the garbage. Some people put fruit and vegetable scraps into their regular compost piles, but this isn't recommended. Food in open compost bins can attract rats. Because they are enclosed, worm bins are rodent-proof.

I hope some of you will be interested in trying a worm bin. Use any weatherproof box with a tight lid. Drill air holes in it. You will need about one square foot of surface for each pound of food waste you generate each week. (See diagram for construction details).

Here's the process -- from "bedding" the worms to harvesting the vermicompost.

Step One: Tear up a stack of old newspapers. (My 1 x 2 x 4 foot bin holds over 10 grocery bags of shredded newsprint.) You don't need to worry about newspaper ink, even on colored sheets, since toxic heavy metals are no longer used in the ink.

Step Two: Fill a wheelbarrow or big tub with shredded newspapers and wet them down. After they have soaked a few minutes, squeeze out the paper and drop it in a pile next to the bin. Let it drain while you wet down the next batch of paper. When the shredded paper is damp, but not dripping, put it into the worm bin.

Step Three: Invite a friend who has a worm bin to dinner. When he or she asks what they can bring, casually mention that a pound or two of worms would be nice. (Assuring them that the worms are intended for you new bin, not the dinner table, is very important at this point.) If this fails, check out commercial sources of worms.

For vermicompost, you need red worms and not earthworms, so you can't just dig them. Earthworms need a mineral soil; red worms or manure worms like a moist, organic muck. Bait shops do sell red worms, but you need a lot to get your colony going, and that could get pricey.

Step Four: Start burying your food wastes in the wormy, bedding-filled bin. Rotate your burying spots to distribute the food evenly. Covering the food with bedding will help control flies and smells. Keep a small bowl or jar next to the kitchen sink to collect "wormfood."

Step Five: When the worms have broken most of the bedding and food into a dark, crumbly compost, push the compost over to one side of the bin. (It will have shrunk in volume.) Fill the empty side with new bedding and start burying your food scraps there. As the worms finish decomposing the old stuff, they will migrate over to the new feeding ground. After a month or two most of the worms will be out of the old compost, so you can remove it from the bin for use in the garden.

If many worms still appear in the finished compost, use their love of darkness to help you return them to the bin. Pile the compost on a tarp or plastic sheet in full sun. After about 15 minutes, scrape off the top worm-free inch or two. Keep doing that until you have a very wormy bottom layer that can go back into your bin or may get you a free dinner from a new, would-be worm composter.

Composting Coffee Grounds

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More information about this topic is available through your local WSU Extension Office