Worm bins (or vermicomposting bins) are basically garden beds devoted solely to feeding and raising worms. They can either be for earthworms or, even better, for red wigglers. There are a few differences between a worm bed and a regular garden bed, but they share many attributes
Advantages of Vermicomposting
Worms are composting factories, eating kitchen scraps and producing rich compost at surprising speed. The compost they produce is richer than most commercial compost and, of course, it's free. Worms work throughout the year, composting even in winter, which means that compost from your worm gardens will be available whenever you need it.
Advantages of Worm Beds
Worm bins are generally multi-layered containers in which red worms eat organic material and produce nutrient-rich compost. Worm bins are small enough to keep indoors, but if you've found that traditional worm bins are just too small for your needs, or you dislike how fussy they can be, worm beds might be a better option.
A worm bed is a good option if you have space and want to try to compost more of your garden and kitchen waste. Even better, you can have a LOT of worms doing your composting for you; instead of a few hundred, you can have thousands of them as they reproduce and keep breaking down your kitchen scraps.
Some gardeners actually build a business around breeding and selling composting worms. As vermicomposting has become more popular, there is more demand for worms. It's easier to set up a worm bed or two outdoors for this purpose, especially if your indoor space is limited.
Raised Worm Beds
The easiest way to build a worm bed is to simply build an ordinary raised garden bed out of wood. These are simple wooden boxes, usually about three feet wide and six feet long, filled with soil and nutrients.
While raised gardens are usually built to take advantage of as must sunlight as possible, worm beds should be in a spot that's shaded for most of the day. The sun will dry out your bedding and make it too warm, especially in the heat of summer. If you don't have a shady spot, consider installing a frame to drape shade cloth over, or make a small shade screen from the lattice.
Dug-In Worm Beds
Your worm bed will work even better if you dig it into the ground, rather than making a raised bed. Simply dig a pit, line the sides with boards, bricks, or cinder blocks (to keep roots from surrounding plants out of your worm bed) and line the bottom with a layer of corrugated cardboard. The worm bed can be any size you'd like, depending on why you're building it and how much space you have available.
Getting Worms, and Caring for Your Worm Bed
You can order red wigglers from many sources online, simply search for "red wigglers" or "composting worms." It's best to order your worms in spring, after the too-cold temperatures of winter and the too-hot temps of summer, either of which can kill your worms in transit.
To maintain your worm bed, simply set it up the same way you would a regular worm bin, just on a larger scale. Shred a bunch of newspaper to use as bedding, moisten it, and layer it into the worm bed. Add your worms, then start adding your food scraps. Keep it moist, but not too wet, and add food regularly. In time, your worms will start reproducing, and you'll have an army of worms working on your behalf.
Tips for Raising Worms
- If you're raising red wigglers, they won't bother digging down into the soil because they prefer to be in decaying organic matter, such as the stuff you'll be filling your bed with.
- If you're raising earthworms, then the worms will move back and forth between the soil and your bed.
- If you want to keep the worms in your bed, consider lining the interior of your worm bed pit with landscape cloth.