Extension Service Garden Hints

Let worms turn your food scraps into beautiful compost

CORVALLIS - Everyone knows that worms help turn a compost pile into rich humus more quickly and efficiently. But few know how to harness the talents of these little creatures, said Linda Brewer, Master Gardener with the Oregon State University Extension Service.

There are two types of worms commonly seen in compost and soil, explained Brewer. Each kind, earthworms and red worms, is different in its eating habits.

"Earthworms are usually larger and are seen in garden soil or in forest litter," said Brewer. "They eat decomposing plant material.

"Red worms, on the other hand, are smaller than earthworms and prefer to eat rich nitrogenous waste like food scraps, manure or the rotting fruit on the ground in an orchard," she explained. "Red worms, rather than garden earth worms are best for processing fruit and vegetable scraps."

More and more people who compost are making specialized worm bins to break down food waste, she said. These worm or "vermicompost" bins are separate from larger compost piles made of yard and other plant debris.

Some Oregon municipalities have composting and worm education programs, said Brewer. One such program is Portland Metro's compost project, with several home compost demonstration centers in Portland tri-county metro area.

To make a worm bin or vermicomposter, get or build a wide, shallow container. A wooden bin, plastic tub with a lid or an old trunk or drawer will suffice, as long as it is between eight and 16 inches deep. Drill holes in the bottom for aeration and drainage. A 48-inch by 20 inch bin will accommodate about one pound (1,000 to 2,000) red worms and will process about seven pounds of fruit and vegetables a week.

Place the bin on brick or blocks for air circulation and protect from freezing in the winter. Place a tray underneath to catch moisture. Cover the bin to provide darkness for the worms and to prevent moisture loss.

Fill the bin three-quarters full with a combination of different bedding materials such as shredded newspaper, office paper or cardboard, brown and dry leaves, straw, peat moss and or sawdust. Moisten the bedding so it is as wet as a wrung-out sponge. Add a handful of soil to give the worms grit to help them digest their food.

To feed the worms, Brewer recommends pulling aside some of the bedding and "burying" the following: your vegetable scraps, fruit peels and pulp, coffee grounds and filters, tea bags and filters and foods like old bread, or crackers. Bury successive loads in different locations in the bin. Do not add liquid dairy products, greasy or oily foods, grains or pet wastes - these may create odors and pest problems. Cover the bedding with black plastic.

Over time, more bedding will be needed, as the worms consume it as well as your food scraps. Always add bedding to keep the bin three-quarters full. Add pre-moistened bedding material by moving the used bedding to one side of the box and filling in the empty space.

Worm bin composters can be kept outdoors in the shade, in the basement, cool shed or garage or under the kitchen counter in a dark cupboard. Remember to move bin to an area that will not freeze in the winter and will not get over 90 degrees in the summer.

After several months, beautiful black "vermicompost" will be in a layer on the bottom of the bin. To remove compost without removing the worms, feed the worms on only one side of the bin a few weeks before removing the compost. The worms will move over towards the food, vacating one side. Remove the compost from the empty side and add new moist bedding to the empty side.

Vermicompost, full of nutrients and humus, can be used on house plants, seedlings and in the garden.

For more information on composting or demonstration compost centers, call your local county office of the OSU Extension Service or call or write for information on vermicomposting and composting from Metro Recycling Information, 600 N.E. Grand Ave., Portland, OR 97232-2736, telephone 503-234-3000.

By: Carol Savonen
Source: Linda Brewer

Email this story

Printer-friendly version

News & Garden Archives