What Is Compost Tea?
Compost tea is a liquid fertilizer made by steeping compost in water. Often called "liquid gold" by organic gardeners, it extracts beneficial microorganisms and nutrients from compost, creating a powerful plant tonic that improves soil health and boosts plant immunity.
Benefits of Compost Tea
Compost tea offers multiple advantages for home gardeners:
- Provides immediately available nutrients to plants
- Increases microbial activity in soil
- Helps suppress fungal diseases when used as a foliar spray
- Improves soil structure and water retention
- Reduces the need for chemical fertilizers
How to Make Aerated Compost Tea
The most effective method involves aerating the mixture to multiply beneficial bacteria and fungi. You'll need:
- 5-gallon bucket
- Aquarium pump with air stone
- Unchlorinated water (let tap water sit for 24 hours)
- 1-2 cups of mature, fully decomposed compost
- Cheesecloth or paint strainer bag
Steps:
- Fill bucket with water and place air stone at bottom
- Add compost in strainer bag (like a giant tea bag)
- Run the pump for 24-36 hours
- Strain and use immediately
Applying Compost Tea
Use compost tea within 4 hours of brewing for maximum microbial activity. Apply in three ways:
- Soil drench: Water plants at root zone once every 2-3 weeks
- Foliar spray: Spray leaves early morning or evening to prevent sunburn
- Seed soak: Soak seeds for 15 minutes before planting to boost germination
Common Compost Tea Mistakes
Avoid these pitfalls for best results:
- Using unfinished compost that may contain pathogens
- Over-brewing beyond 48 hours (can turn anaerobic)
- Applying in full sun (can burn leaves)
- Storing instead of using fresh
Scientific Support for Compost Tea
Research from universities including Washington State University confirms compost tea can improve plant growth and suppress diseases like powdery mildew when properly prepared. However, results vary based on compost quality and application methods.
Advanced Compost Tea Recipes
Experienced gardeners often add ingredients to target specific needs:
- For fungi-dominant tea: Add 1 tbsp molasses
- For bacterial-dominant tea: Add 1 tbsp unsulphured molasses
- For pest defense: Include comfrey or stinging nettle leaves
This article was generated by an AI assistant based on trusted gardening resources. Always test compost tea on a few plants before full application.