Compost Tea: How to Make and Use This Liquid Garden Tonic

Compost tea—a liquid extract of compost—has been used for centuries as a natural fertilizer and soil health booster. It delivers beneficial microbes and nutrients directly to plant roots and foliage. Two main methods exist: passive (simple, weeks to brew) and aerated (faster, requires equipment).

Passive Compost Tea (Easy, Low-Cost)

• Ratio: 5 parts water to 1 part compost. Use rainwater or dechlorinated tap water (let sit 24 hours).
• Place compost in a burlap sack, suspend in a 5-gallon bucket of water.
• Steep 2 weeks, stirring daily or every other day.
• Remove bag; apply liquid to plants.

Aerated Compost Tea (Faster, More Microbes)

• Adds ingredients like kelp, fish hydrolysate, humic acid.
• Requires air/water pumps (commercial brewers available or DIY with aquarium pump and bucket).
• Ready in 2–3 days. Stir a few times daily.
• Can strain later or use a sack/pantyhose for compost.

Notes

Pre-brewed compost tea is also sold at some garden centers. Both methods enrich soil biology, improve plant resilience, and reduce dependency on synthetic fertilizers.