How to Grow Mealworms

Mealworms are a great addition to any compost pile. Not only are they easy to grow, but they produce large numbers and make an excellent fertilizer. A mealworm’s waste also makes a wonderful soil conditioner and can be used directly in your garden. 

How to grow mealworms? Before you start growing your own, though, be sure you understand the care and feeding that’s involved with a successful home mealworm farm.

You’ll need a small bin, a food source, bedding, and water. For the bedding, try using bran flakes or whole oats and add a 2-inch layer to your container. Mealworms can’t live without their substrate and rely on it for warmth, nutrition, and hydration. Mealworms are also very sensitive to the environment, so it’s important to keep your worm farm in a dark, warm place that doesn’t smell too bad.

Ideally, the bin you choose should be shallow and plastic to prevent the worms from chewing through it or climbing on it. You should also use a clear bin so that you can easily see the frass (worm poop) that builds up on the bottom of the container. The worms will eat this sand-like material, and you’ll need to sift it out occasionally to remove dead worms or squirmy beetles. The sifted mealworm “waste” is actually an excellent natural fertilizer, so don’t throw it away! You can add it to your garden or compost pile, or use it to mulch plants.

To feed your worms, cut up pieces of potato or carrot and scatter them throughout the bedding. Mealworms can also be fed dried grains, such as bran flakes or whole oats. If you decide to use this option, be careful about the type of grain you choose – many chicken feeds contain diatomaceous earth and will quickly kill your worms.

As the worms eat their way through the bedding, they will leave behind a layer of dark, sand-like waste. This is called frass and is a good sign that your colony is healthy. You can remove this frass and put fresh bedding in as needed.

Aside from making sure that the containers have plenty of air flow and don’t get too hot, there are few problems associated with mealworms. The biggest problem is mold, which can be caused by too many watery fruits or vegetables, poor ventilation, and extreme humidity. If your colony starts to grow mold, it’s important to remove it and completely clean the container before adding new bedding and worms. Be sure to wipe down the walls and lid of the container with diluted bleach water before you return your worms to it.