Vermicomposting is using worms to convert kitchen and garden scraps into rich, organic fertilizer. Worms eat the scraps and produce castings or vermicompost as waste. As nature would have it, the worm's waste is a gardener's treasure trove, full of plant nutrients and beneficial microbes.
You could buy a vermicomposter, but making your own can be more economical and rewarding. With or without handyman skills, you can construct a functioning wormery for reycling organic household waste and boosting plant growth.
Worms that consume vegetable waste and other organic matter produce richer casting than those that only feed on plain soil. The best vermicomposting worms are red wigglers and redworms. These species are generally easy to keep and prefer a compost environment. Although you may find either species in your garden, it is difficult to distinguish them from other worms. If you don't have a local source, order your worms online. You'll need about one pound of worms — around 1,000 individual critters — to start your worm bin.
Where you place your worm farm is an important factor in its success. Fortunately, a simple one will not require much space. If your bin will be outside, avoid temperature extremes. The best option is indoors in a garage or basement. With the proper setup, your little farm should not produce any offensive odors.
Get two plastic bins of the desired size with slightly tapered sides that make nesting easy. They should be opaque, with a top to keep the light out and the worms in. One needs to be taller to rest inside the shorter bin. The lower one will be the sump bin that collects your worm tea or vermitea.
Made to be good insulators, styrofoam containers are also a great option for building a worm farm. Old tires or barrels placed on a platform can function as vermicomposters, too. You can even build a home for your hard-working creatures with old bricks.
Drill holes near the top of the larger bin so that the worms can breathe. You’ll also need to drill holes near the bottom to let excess water drain, so you don't drown your worms. Install a small flower pot or some blocks between the bins to improve ventilation and drainage. Cover both sets of holes with a fine vinyl screen to keep the worms inside and other creatures out. Avoid metal screening, which will rust when exposed to the moisture inside the bin.
Create a comfy space for worms to thrive with fibrous bedding and organic food scraps. Dampen and fill your top bin with about three inches of shredded paper or coconut coir. Add about a pound each of damp soil and household scraps. Now, the farm is ready to welcome worms.
Lightly cover the worms and scraps with more shredded paper to deter insects, and keep the lid snugly closed. Add more organic scraps after a few days. Sprinkle water over the bedding — the farm should stay moist but not soaking. Change out the newspaper once a week.
Within a few weeks, the worms will be busy reproducing and the compost will build up. Once it collects to your desired level, take out the vermicompost for its intended use. Siphon the vermitea from the sump bin. This liquid is a highly concentrated fertilizer that you can dilute 1:1 with water and use right away in your garden.
After a while, swap the positions of the bins, placing the bottom bin on top. Set up the new top bin with new bedding, a small amount of castings from the old top bin, and kitchen scraps. The worms will migrate upwards towards the new food. You should be able to harvest more vermicompost within three weeks of the switch-out. Alternate the bins regularly.
Proper bin maintenance and worm care can help prevent many common vermicomposting problems. Feed your little composters the right foods, and don't overfeed them. Ensure sufficient airflow and check the drainage regularly for any blockage. Keep your worms comfortable within a suitable temperature range and proper moisture levels. Too much moisture can drown them, but if their skin dries out, the worms will perish.
Temperatures exceeding 95° F will likely harm or kill your worms. If necessary, move the worm bin to a cooler area. Reduce nitrogen-rich foods, which may be heating up the bin. Add extra bedding as an insulator. Create a cool zone on hot days by placing a frozen water bottle in some newspaper and burying it in the bin.
Conversely, temperatures of 40° F or lower will also kill your squiggly workers. Create more heat by adding grass clippings or other nitrogen-rich organic matter. Insulate the bin with cardboard, wool, or fabric. Move the worm bin inside or to a warmer location. A heat lamp can help warm things up as well.
If your worm bin’s environment is too acidic or moist, it could produce an off-putting smell. Gently turn over the contents to aerate the bedding. Add pH-neutral materials such as crushed eggshells, garden soil, and crushed lime. Space out the feedings more, and remove rotting or moldy foods. Add fresh bedding to soak up excess moisture.
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