To have the best vegetables and plants you need amazing compost. Unati, the horticulturist at Flower Valley Farm, explains how she re-used an old bathtub to make an earthworm farm at the outdoor classroom.

How to set up an earthworm bathtub?

You will need a bathtub (or another container) cardboard boxes, newspapers, soil, food scraps, and some earthworms to start your worm farm.

First, select a container that is suitable for your composting needs. At Flower Valley farm we used an old bathtub, which is big enough for our composting and gardens.

Choose a cool place for the bathtub to be placed. Earthworms dislike areas that are too warm or wet.

Make sure that the container is lifted enough to drain away the liquid from the worm compost.

Using wet cardboard boxes, place layers at the bottom of the bath until it is 10-15cm thick, and then add the worms and food scraps. Add more food scraps and plant debris to cover worms.

Sprinkle soil lightly over the food scraps or plant debris to keep the compost moist, and cover the bath to avoid sun or rain coming in.

The paper and cardboard (bedding) should be kept moist, but not soggy, and the top 15 to 18 cm turned every 7 to 10 days to keep it loose.

About every 6 to 9 months the old paper should be replaced with properly prepared new paper bedding (moist and brown). To change bedding, remove the top 12or 15 cm (where most of the worms are).

The breeding cycle is approximately 27 days from mating to laying eggs. Worms can double in population every 60 days.

Benefits of earthworm composting

The liquid collected at the base of the bathtub makes a concentrated bio-fertilizer that can be used in the following ways:

– The raw earthworm liquid can be applied directly onto non-edible plants like flowers, trees, and bushes.

– Dilute the worm liquid with water and add it to the compost pile as a compost activator.

– For edible plants, the earthworm compost needs to be filtered. This can be done using a pillowcase. Put the raw liquid into the pillowcase and leave it overnight in a container. This removes all particulates, and produces an earth worm tea, which is a “super juice” for vegetables. This liquid needs to be used within 48 hours.

The Flower Valley earthworm farm is now ready for composting and making earthworm tea for our gardens.