What is the shelf life of worm castings?

The shelf life of worm castings, also known as vermicompost, is relatively long. When stored in a cool, dry place, away from direct sunlight, worm castings can maintain their efficacy for up to two years or more. While the nutrient content may gradually diminish over time, the beneficial microorganisms that enhance soil fertility and plant growth tend to remain active. To ensure maximum effectiveness, it is recommended to use fresh worm castings within the first year. Proper storage in sealed containers or bags can minimize exposure to moisture and help preserve their quality. Nevertheless, it's essential to conduct periodic quality checks, such as inspecting for mold or odors, before using older worm castings to maintain optimal gardening results.