Earthworm Castings For Houseplants

Why worm poop is good for your plants.

As the outdoor temperatures fall we are focused more on the indoor greenery. Whether your houseplants were put outside for the summer or not, the days are getting shorter and these plants often respond by dropping a few leaves. Don’t worry about this, because it’s a natural response to the shorter days. Since the nights are getting longer, most houseplants are not actively growing at this time of year, so with the exception of citrus trees and some winter-flowering species, we don’t feed interior plants with synthetic plant foods now. But there is a way to organically improve the health of houseplants at this time of year: worm poop!

Studies have shown that worm castings contain rich microbiological colonies that can help fight soil-borne plant diseases and repel insects. Castings won’t burn even the most delicate of plants, yet they are water-soluble so plants can quickly and easily absorb essential nutrients and trace minerals.

We stock the organic Wiscasset Blend Earthworm Castings from The Coast of Maine. These are natural but odorless, so are perfect for top-dressing existing houseplants in the fall or winter. You can also add earthworm castings to the mix when repotting a plant, or stir them into your watering can to make a compost tea. Tip for earthworm tea: Add castings to water in a can, stir and let sit for up to an hour. Stir again and then water the plants. Don’t let such brews sit for days at a time: use it the same day you mix it up.

A good rule of thumb is to use 2 Tablespoons of castings in small, 6″ pots, and up to 8 Tablespoons in 24″ pots. Earthworm castings will not burn plants, so don’t worry that you might use too much.