Worm tea: organic fertilizer and natural pesticide
Worm tea is worm castings brewed in water with molasses. For 20 litres / 5.29 gallons: 1 kg / 2.2 lb of castings + 25 ml / 1 tbsp molasses in chlorine-free water, aerated with an air pump for 24 hours. Use it within 24 hours for best results, pure or diluted 5 parts water to 1 part tea.
When I talk about worm tea (some people also call it compost tea), many people still smile or look a little perplexed, wondering what on earth I am talking about. But more and more garden enthusiasts and farmers are learning about the outstanding benefits of this organic plant food.
Shrubs, trees, flowers, vegetables, seeds, seedlings and lawns all benefit from it.
What is worm tea?
Worm tea is produced when worm castings are mixed with water and molasses and brewed for 24 hours. The molasses is food for the beneficial microorganisms in the worm castings, and the brewing multiplies them rapidly.
Liquidized worm castings:
- act as a natural fungicide and insecticide
- can be used as an organic fertilizer
- will never burn plants
- improve soil structure and plant health
You will need: a bucket or tank, an air pump with some piping, an air stone (as used for fish tanks), worm castings, molasses and water. Don’t have castings yet? Start with a worm farm.
How to brew worm tea (20 litres / 5.29 gallons)
1Fill the bucket with chlorine-free water
Pond water is ideal. If you only have tap water, add the air stone, switch on the air pump for 12 hours and let the chlorine evaporate.
2Add the worm castings
Add 1 kg / 2.2 pounds of pure worm castings.
3Add the molasses
Add 25 ml / 1 tablespoon of molasses.
4Aerate for 24 hours
Let the air pump run for 24 hours.
Worm tea brewing in a bucket 5Remove the air stone and use it
You can use the tea immediately. It gives the best results within 24 hours after brewing, but stays beneficial for several months. If you bottle it, shake it before use to activate the remaining microorganisms.
Worm tea ready to be bottled
Using worm tea
- As a foliage spray: filter it through a cloth first, so solids don’t block the sprayer.
- Diluted: properly prepared tea can be used pure, but it is fine to dilute it. 5 parts water to 1 part tea still brings great results.
Your worm farm’s bottom tray also collects liquid; see step 7 of starting a worm farm. Try the recipe and tell us about your experiences! A brewing log in the Easy Worm Farming Planner helps you compare batches.
