Most of us have heard of worm bins (or vermicomposting bins), but what is a worm bed? Why would a gardener want one? And how do you build one?
Worm beds are basically garden beds that you devote 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, and we'll get into those in a second.
Why Start a Worm Bed?
A worm bed is a good option if you have the space and want to try to compost more of your garden and kitchen waste. 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. Finally, you can have a LOT of worms doing your composting for you; instead of a few hundred, you can literally have thousands of them as they reproduce and keep breaking down your kitchen scraps.
Which leads us to the second reason to start a worm bed: 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.
How to Build a Worm Bed
While you can just build a regular raised bed out of wood for your worm bed, there are a couple of things to keep in mind.
The first is that no matter how you build your bed, it 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 lattice.
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. If you're raising red wigglers, they won't bother digging down into the soil -- 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.
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, you worms will start reproducing, and you'll have an army of worms working on your behalf.