How to Make Vermicompost (Worm Composting) Step by Step

Updated 2026-07-11 · Soil & compost

Vermicompost turns kitchen and farm scraps into one of the richest soil amendments you can make — worm castings that are alive with biology and gentle enough to plant straight into. It is cheap, odourless when done right, and works from an apartment tote up to windrow scale. Here is how to run a bin that thrives.

Use the right worm

Composting worms are not the earthworms in your garden. Use red wigglers (Eisenia fetida) — surface-dwelling, fast-breeding, and happy in a crowded, rich bin. European nightcrawlers (Eisenia hortensis) also work. A starter pound (roughly 1,000 worms) seeds a household bin and multiplies to match the food supply.

Set up the bin and bedding

• Container: a shallow, ventilated bin (plastic tote or purpose-built worm tower) with drainage holes; worms feed near the surface, so wide and shallow beats deep.
• Bedding: fill two-thirds with moist carbon bedding — shredded cardboard, newspaper, coir or aged leaves — dampened to a wrung-out-sponge feel.
• Site: keep it in the 55–77°F (13–25°C) range, out of direct sun and hard freezes — a garage, basement or shaded spot is ideal.

Feed for a balanced bed

Bury food scraps under the bedding in one corner at a time and let the worms catch up before adding more.

Feed: vegetable and fruit scraps, coffee grounds and filters, tea, crushed eggshells, and more carbon bedding to balance wet food.

Avoid: meat, fish, dairy and oily/greasy food (odour and pests); large amounts of citrus, onion and garlic (too acidic); and salty or heavily processed scraps. If the bin smells, you are overfeeding or it is too wet — add dry bedding and pause feeding.

Harvest castings and make worm-compost tea

In roughly 3–6 months the bedding becomes dark, crumbly castings. To harvest, push finished material to one side and add fresh bedding and food to the other; the worms migrate over in a couple of weeks, letting you scoop out nearly worm-free castings.

• Use castings as a potting-mix booster (10–20%), a transplant pinch in the hole, or a top-dress side-dressing around plants.
• Worm-compost tea: steep a shovelful of castings in dechlorinated water (aerated is best) and apply as a soil drench to introduce biology — use it fresh.

Any liquid that drains from the bin ("leachate") is not the same as tea — dilute it heavily and use only on non-edible plants, or avoid it.