How to Start a Worm Farm

Medically Reviewed by Dany Paul Baby, MD on November 07, 2022
5 min read

Composting is a popular way to keep food waste out of landfills and create a natural fertilizer for houseplants and gardens. Worm composting takes advantage of earthworms’ natural ability to break down food scraps into rich, safe compost material. 

Setting up a worm farm will allow you to recycle food scraps at home. The worms will get to work processing the food into compost material. Within a few months, you’ll have your own fertilizer to use or share with fellow gardeners.

A worm farm is a type of composting system known as vermicompost. You set up a container filled with damp paper, earthworms, and food scraps for the worms to eat. The worms digest the food scraps and excrete a substance called castings.

Worm castings contain nutrients from the food they digested, which is good for the soil and the plants that grow in it. In nature, worms burrow through the ground and leave the castings behind, which improves the overall quality of the soil. The compost from a worm farm offers the same fertilizing benefits to gardens and houseplants.

You can start a worm farm by buying a worm farm kit and setting it up. You can also build your own worm farm using a large container such as a plastic storage bin or an old aquarium. The container should have a capacity of five to 10 gallons and be wider than it is deep. The bin will need a lid so the worms can’t crawl out.

You may want to place the worm bin in another container to catch any drainage from the compost. Some experts suggest drilling holes in the bottom of the worm bin to allow liquids to escape. The second bin holds the drainage. This prevents fluid from accumulating and drowning the worms. Place a mesh material over the holes so the worms can’t escape.

Clean the bin and fill it with shredded paper and about a pound of soil. Add enough water to soak the paper. Drain off any water that doesn’t get absorbed by the paper and dirt. This will form the bedding for your worms.

Experts recommend using red wiggler worms for worm composting. These worms are efficient at consuming food scraps and other waste. Avoid invasive species of worms, such as the Asian Jumping Worm, also known as the Alabama Jumper or Georgia Jumper.

You can purchase worms from worm farming supply sites or get worms from another person who makes worm compost. The worms reproduce quickly, so the population in the bin will grow.

Once you have worms, you can add them to the prepared bedding. Give them a day or so to get acclimated before giving them food scraps to eat.

You will need to keep your worm farm indoors all year round. Worms don’t do well in extreme temperatures. Choose a location where the worms won’t get too hot or too cold.

You can feed worms a variety of plant-based food scraps. Vegetables, fruit, tea bags (without the staple), and coffee grounds are all good materials for feeding worms. Meat and dairy products are appropriate for worm farms.

To feed the worms, dig a small hole in the top six inches of the soil for the food scraps. Cover them completely to avoid attracting insects. Add more food only after the worms have eaten all the scraps you left previously. You may find that they avoid some types of scraps. If they don’t seem to like something, remove it from the bin and make a note not to offer it again.

After three to five months, there will be enough compost that you will be able to harvest it. To do this, you need to separate the worms from the compost and leave the worms behind. There are several ways to accomplish this:

  • Move all the compost to one side of the bin. On the empty side, add fresh bedding material and food scraps. Over the next few days, the worms will move to the area with food. You can scoop out the compost and remove any lingering worms.
  • Leave all the compost in place but place food scraps off to one side. The worms will migrate, and you can remove the portion of the compost that the worms have left.
  • Scoop piles of compost out and sort the worms out by hand. Replace the worms in the bin as you go.

Once you have harvested the compost, you can add more bedding of moist shredded paper if the worms need it. You should also add food scraps, since you will have removed the worms’ last meal.

The end product of your worm farm will be a rich compost that you can add to potted plants or your garden. Worm compost contains soil nutrients like nitrogen, phosphorus, and minerals important for plant growth. Unlike chemical fertilizers, it won’t damage plants or affect groundwater near your home. Worm compost is organic and good for the environment.

To use worm compost in potted plants, simply place a mulch layer over the potting soil. Remove any worms left in the compost; they won't like being stuck in a small pot. The nutrients will leach into the root area of your plants each time you water them. You can also mix the compost with potting soil and add it to an already-potted plant or pot new plants in the mixture.

You can add a layer of worm compost to outdoor gardens as a fertilizer and soil amendment. Adding compost several times per year will improve soil quality and nourish plants. Spring and fall are typically good times to add compost. If you have more compost than you need, you can share it with friends or neighbors.

For more worm farm tips and information about local worm farming supplies, contact a garden center or plant nursery.