Worm Poo!!!
Ok… Worm Castings
Castings is just a fancy word for worm poop — and it's some of the best stuff you can give your garden.
Castings are the end result of worm-digested bedding and food scraps. While the worms are digesting organics, many insoluble minerals are converted to plant-available soluble forms. Worm castings are several times richer in available nitrogen, phosphates, and potash than traditional compost, and contain 10 to 20 times more microbial activity.
Each casting is encased in mucus, which helps soil retain moisture. They can be mixed into soil at a ratio of 1:3 to 1:4 with other soils, used as a top dressing, or brewed into a liquid "worm tea" fertilizer.
How Do I Harvest the Castings?
1 — Box, Dump, and Sort
Works on the principle that compost worms always move away from a light source.
- Place a large plastic sheet on a flat surface and pile your castings into several mounds.
- Begin removing the very top layer and the castings around the base of each mound.
- Wait a few minutes between removals to allow worms to bury back down to the bottom.
- You'll be left with a pile of worms at the bottom, easily separated from the remaining castings.
2 — Box Migration
Works on the principle that worms will migrate toward fresh food when their current bedding is depleted.
- Stop feeding for about a week (excess food can go in the freezer for later).
- Push all old bedding to one side and add fresh bedding and food on the other.
- For the next couple of weeks, only add fresh food to the new side.
- Once all worms have migrated, remove the finished castings from the old side.
3 — Flow Through System
Works on the principle that compost worms are surface and shallow dwellers — they follow the food upward, leaving finished castings below.
Note: flow through systems only work with red compost worms, not other earthworms that make deep burrows.
Tower systems can be constructed from layered bins with mesh bottoms. To harvest, simply empty the bottom bin. These systems are essentially hands-free and come in many varieties.
Timing: Your bin should take about 3 months from start to harvest. Once harvested, store in a breathable bag, use right away, or brew into worm tea.
What Can I Do With My Castings?
Natural Fertilizer
Add castings to potting soil for new plants or baskets at a ratio of roughly 1 part castings to 3 or 4 parts soil. They can also be used as a top dressing for house plants, or dug directly into outdoor garden beds and flower beds. Great for balcony pots — instead of replacing heavy soil, just feed it!
Tea Anyone?
"Worm Tea" is made by steeping castings in water for a few days while stirring to add oxygen. The resulting brown liquid is used as a fertilizer for indoor and outdoor plants. When placed in a fine mesh "tea bag," it can be used in a spray bottle as a natural pesticide to help combat pests. Like composting, worm tea can be as simple or elaborate as you like.
Important
Worm Tea is best used within a day or two of brewing. It should smell like fresh soil and rain. If it begins to smell off, do not use it — the beneficial microbes have gone anaerobic.
Simple Worm Tea
You'll need a bucket, worm castings, and water. There's no exact ratio, but use approximately 4 litres of water per cup of castings. Use non-chlorinated water (rainwater is ideal), or let tap water sit for 24 hours to allow chlorine to dissipate.
- Place the castings directly in the water, or if using as a spray, put them in a fine mesh bag or old sock to prevent clogging the sprayer.
- Stir often to add oxygen and let the tea steep for 12 to 24 hours.