Published in the March 16- 29, 2016 issue of Morgan Hill Life

By Glenn Lattig

Glenn Lattig

Glenn Lattig

You have these kitchen scraps — potato peels, lettuce leaves, coffee grounds — and you really don’t want to put them in the garbage where they go to the landfill or put them down the disposal. You think it’s a hassle to put them in the backyard compost pile (if you have one) with the matching of green material with brown material, and turning it once a week. What can you do with them?

You can start a worm bin and “recycle” your scraps into incredibly rich worm castings that you can use in place of expensive fertilizers on both indoor and outdoor plants. You can make your own worm bin using old recycling containers, or old fence boards, or you can purchase a commercial bin through a garden supply catalog. The county will assist you in starting a worm bin.

Contrary to popular belief, worms are really quite clean and the castings they leave — worm poop — are virtually odorless. Worms breathe through their skin, so they have a light mucus on them to keep their skin moist. This mucus is not slimy or dirty. In fact, it will kill e-coli bacteria on contact.

The worms used for vermiculture — composting with worms — are not earthworms. They live in decaying organic matter such as leaves. The common one used is the red wiggler or manure worm, Latin name eisenia foetada.

Worms are hermaphroditic — they have both male and female sex organs, but it still takes two worms to reproduce. They form a self-regulating population adjusted by the size of the worm bin and the amount of food provided.

So let’s set up the worm bin. As a general rule, for the average household a bin with a surface area of two to four square feet is appropriate. It should sit off the ground and have holes on all sides. It should be situated out of direct sun. Ideal temperature range for the worms is between 55 and 77 degrees. They can handle hotter and colder temperatures for short time periods. A garage works fine.

Next put in about four inches of bedding material. The easiest material to use is shredded newspaper. Do not use the glossy magazine inserts. The shred should be between 1/8 and 3/8 inches in width. If you have a shredder that turns your paper to confetti, don’t use it. It will form paper mache and smother the worms.


Now the food goes in. Worms will eat most kitchen scraps. Exceptions are meat or dairy, oils, citrus, leaves or yard clippings, soil, and strong aromatics like garlic and heavy spices and peppers. Their digestive tract is like that of a chicken — a crop and a gizzard. They have no teeth,therefore, they need coarse material in the crop and gizzard to grind the food. Coffee grounds and ground up egg shells work just fine. Cover the food with additional shredded newspaper and moisten. This keeps out fruit flies. Feed the worms about one pound of food per square foot of surface area per week.

When you have built up a reasonable amount of castings (bedding and food gone, rich brown material in its place — this will take a while), it’s time to harvest. Keep the castings and return the worms to the bin.

A source of red wigglers is Jerry Gach in San Jose. He can be reached at For more information about vermicomposting, call (408) 918-4640, or Morgan Hill offers composting workshops in May and September.

Glenn Lattig is a master gardener and master composter. He wrote this column for Morgan Hill Life.