Let the worms do the work! Build your own worm farm for composting

What is a Worm Farm?
Worm Farm
Building a Worm Farm.

Worm farming, or vermicomposting, is a way to recycle food waste using worms. Worms are housed in an enclosed compost bin, or worm farm, and are fed food scraps. The worm farm is completely closed so that the worms stay in one place to feed, digest and excrete. Worm farms can be purchased, but it is easy to build your own worm farm with a few simple supplies.

Why Build a Worm Farm?

As worms break down the food scraps, they leave behind a valuable garden supplement: their castings (or worm poop)! Worm castings are a nutrient-rich soil amendment that can be used just like any other type of compost. Since worms only eat kitchen scraps, vermicomposting is an ideal method of composting if you have a lot of kitchen scraps or live in an apartment building. Worm farms are small, easy to manage, and can be kept indoors.

How to Build a Worm Farm
  • Materials Needed for Constructing a Worm Farm
  • Opaque 8-10 gallon plastic storage bin with lid
  • Drill with ¼ and 1/16 inch bits
  • One extra storage bin lid (this will be the base)
  • A few dozen (non-glossy) sheets of newspaper (or peat moss)
  • ½ cup fresh compost
  • One pound red worms (Eisenia fertida)
  • Large piece of cardboard, cut to fit flat into the bin
  • 2 bricks (optional)

Building the Farm
1. Using the ¼ bit, drill about 2 dozen drainage holes in the bottom of the bin. Using the 1/16 bit, drill a row of ventilation holes in the sides of the bin, spacing them 1 ½ inches apart and 2 inches from the top. Drill several dozen ventilation holes in one of the lids.

2. Shred newspaper into one inch-wide strips. Soak the strips in non-chlorinated water, then squeeze them so the paper is damp, but not dripping. Add the paper to the bin with the compost, mixing and fluffing until the bin is about ¾ full. The newspaper will act as bedding and the compost will supply grit to help the worms digest their food.
Use peat moss – soaked in non-chlorinated water (rainwater or pond water) for 24 hours. Squeeze water out of peat moss until it is like a moist sponge and fill bin ¾ full as bedding.

3. Add the worms to the bin. Dampen the cardboard and set it gently on top of the worms. Cover the bin with the drilled lid. Place your bin outdoors in a sheltered place or indoors in a well-ventilated area.

Worm Farm Maintenance

Worm Food

  • Fruit and vegetables scraps (no citrus, pineapple, onions, garlic, meat, dairy or oils)
  • Bread, cereal, coffee & filter, tea bags, egg shells (washed and finely crushed)
  • Dryer lint, vacuum cleaner dust, hair clippings
  • There is also a commercially produced Purina Earthworm Chow available at feed stores.

How much food?
The first few weeks give them about one cup of a day. If you notice an odor, cut back. There should be only a “woodsy” smell to the worm bin.

Do I add water?
This is helpful if you want to collect “worm tea” . Use only rainwater, pond water or tap water that has sat in the sun (to eliminate the chlorine).

How to get the worms out and harvest the compost?
After about 12 to 16 weeks, stop feeding the worms for a week. Remove any large scraps of food. Push everything to one side of the bin. Then, add fresh bedding and food to the other side of the bin. In a couple of weeks most of the worms will have migrated to the side containing the food, leaving behind a nice pile of compost to mix with your potting soil. There is no need to remove worms or eggs from your bin unless you want them to start a new worm farm.

Worm Farm

After 40 days or so, you should have two or three times as many worms as you started with. You might notice some eggs: yellowish pellets about the size of a match head that contains 4-20 tiny worms.

Worm manure
Vermicompost is clean smelling and makes a good garden fertilizer. A good potting soil recipe is a mix of ¼ worm castings, ¼ perlite, ¼ peat, and ¼ builder’s sand. If you would like to create tea, place castings in burlap bag or pantyhose leg and tie off. Place the bag into a bucket of water and leave overnight. Use tea to water plants or as a foliar spray.

Click here for the fact sheet (pdf) of this blog post.

For more information, contact UF/IFAS Extension Polk County at (863) 519-1041 or visit us online at http://sfyl.ifas.ufl.edu/polk. The Plant Clinic is open Monday-Friday, 9:00 am-4:00 pm to answer your gardening and landscaping questions. Give us a call, or email us at polkmg@ifas.ufl.edu.

If you are not in Polk County, Contact your local UF/IFAS Extension Master Gardener Volunteer Plant Clinic.

The Florida Master Gardener Volunteer Program is a volunteer-driven program that benefits UF/IFAS Extension and the citizens of Florida. The program extends the vision of the University of Florida/Institute of Food and Agricultural Sciences, all the while protecting and sustaining natural resources and environmental systems, enhancing the development of human resources, and improving the quality of human life through the development of knowledge in agricultural, human and natural resources and making that knowledge accessible.

An Equal Opportunity Institution.



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Posted: April 21, 2020

Category: Home Landscapes,
Tags: Anne Yasalonis, Ayasalonis, Central Florida, Compost, Composting, Florida-Friendly Landscaping, Gardening, Master Gardener, Master Gardener Volunteer, Polk County, Polkgardening, Polkmg, Vermicomposting, Worm Composting, Worm Farm

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