Vermiculture, also known as worm composting, is the process of using worms to convert organic waste into nutrient-rich compost. This organic waste includes kitchen scraps, yard trimmings, and other biodegradable materials which break down and are eaten by worms. The worm excrement, more commonly referred to as worm castings, is then applied to or mixed in with the soil. Vermiculture is an environmentally-friendly way to recycle and reduce waste while creating a valuable resource for your garden.

Adding worm castings to your soil offers numerous benefits. In no particular order of importance, here are some key advantages of vermiculture:

Nutrient-Rich Soil Amendment: Worm castings are a nutrient-rich soil amendment. It improves soil fertility by adding essential nutrients enhancing plant growth and health. They don’t call it black gold for nothing.

Free, Fresh Worm Castings: Vermiculture requires little up-front expense to get started, and then provides continuous worm castings for as long as you keep worms. Store bought worm castings are expensive and have usually been sitting on the shelf for a while before you are purchasing them. The longer worm castings sit on the shelf, the more moisture it loses and the more the nutrients degrade.

Improved Soil Structure: Just like garden compost, worm castings enhance soil structure by improving its texture, water retention, and drainage. It helps create a more crumbly and well-aerated soil, providing a healthier environment for plant roots.

Water Conservation: Over time and multiple applications and/or in conjunction with garden compost or other soil amendments, worm castings improve the soil structure allowing the soil to retain water more effectively. This can lead to water conservation in gardens and landscapes.

Reduction of Soil Erosion: Again, over time and multiple applications and/or in conjunction with garden compost or other soil amendments, worm castings help prevent soil erosion by stabilizing soil structure and reducing runoff. This is particularly beneficial in areas prone to erosion.

Disease Suppression: Beneficial microorganisms that can suppress certain plant diseases are found in fresh worm castings. Using worm casings as a soil amendment creates a healthier environment for plants and reduces the risk of soil-borne pathogens.

Waste Reduction: If done on a larger scale, vermicultre can reduce the amount of organic waste that goes to landfills. Kitchen scraps, yard trimmings, and other organic materials are diverted from the waste stream and reduces the environmental impact associated with landfilling.

Promotion of Sustainable Gardening: Vermiculture supports sustainable gardening practices by providing an eco-friendly alternative to synthetic fertilizers and soil amendments. It aligns with principles of organic and environmentally conscious gardening.

Starting your own vermiculture bin is a simple and rewarding process. Follow these steps to get started:

Choose a Bin: Select a suitable container for your worm bin, such as a plastic storage bin with a lid. Ensure that it has adequate holes for air flow. If you choose a plastic storage bin, you can drill approximately 1/8″ holes into the lid. There are also a number of commercial worm bins to choose from if you’d rather purchase a ready-made bin.

Bedding Material: Worm bedding creates a comfortable and suitable environment for worms. It serves as both a habitat for the worms and a medium for the decomposition of organic waste. Create a bedding using moistened shredded newspaper, cardboard, coconut coir, or aged manure. A combination of beddings can be even better. The bedding should be a depth of 6-12″.

Pick a Place for Your Worm Bin: Pick a suitable spot to place your worm bin. Optimal temperature should range between 55°F to 77°F, as worms thrive in these conditions, although compost worms can generally survive temperatures between 40°F and 90°F. If you choose to keep your worm bin outside, be mindful of large temperature fluctuations, and keep the worm bed shaded as direct sunlight can heat a worm bin too much similar to how the inside of a car heats up on hot days.

Add Worms: There are a variety of worm species you can choose for your worm bin, but we’d recommend red wigglers (Eisenia Fetida). Prior to adding worms, add a small amount of kitchen scraps to the fresh bin allowing the decomposition process to begin. Start with no more than one pound of worms for every square foot of surface area, although we’d recommend starting out with a maximum of one pound of worms (or even less) in order to get comfortable with vermiculture.

Vermiculture bins are very easy to maintain. Be sure to keep bins in a place that stays warm enough, yet also take precautions to prevent overheating if bins are kept outside during the warmest months of the year. Regularly monitor the moisture in your bin. If conditions get too dry, the worms will die. Worms are 75-90% water by weight. Add water as necessary to maintain moisture, but also be aware that kitchen scraps can also add moisture.

Begin adding small amounts of kitchen scraps, vegetable peels, coffee grounds, and other organic waste to the worm bin on a weekly basis. Avoid feeding them meat, dairy, oily or greasy foods. Be careful not to over-feed the worms only adding more food once the last food has been eaten. More than average food amounts can be added if you will be away for an extended period of time. When feeding, add in some new bedding material.

Worms reproduce naturally in a vermiculture bin, ensuring a continuous population. When conditions are favorable and food is abundant, worms lay eggs in cocoons. Each cocoon contains multiple baby worms, and these cocoons hatch in about three weeks. With proper care, worm populations can multiply rapidly, allowing for more compost production. When the worms population increases significantly, you can separate the worms and start a second worm bin, if desired. If the worm population reaches capacity for the bin, the worms will stop reproducing on their own.

The most effective way to use worm castings in the garden is to mix them in with your soil. You can mix worm castings into the soil before planting or you can use them as a side dressing around the base of established plants. A small amount of worm castings can be beneficial to plants. The maximum recommended use is approximately 20% of the soil-mix. While more will not do harm, you may not see additional benefits. 

Worm castings may also be used to make a compost tea by steeping worm castings in water for several days. Although we think adding worm castings directly to the soil provides the maximum amount of nutrients, feel free to experiment and see what works best in your garden.