Scot Nelson

Compost tea is made by steeping compost in water. The tea serves as a foliar fertilizer or as a soil nutrient and microbial drench. Producing compost tea is an art as much as a science. Types of compost tea include:

1. FRESH. Steep healthy compost in water for a brief time and apply the liquid to plant leaves or soil. It may have viable plant pathogens, but the heat of composting kills most of them.

2. FERMENTED, WITH AERATION. Compost is fermented in water infused with a constant stream of air bubbles to promote oxygen-loving aerobic bacteria and fungi. This type of compost tea smells good (not stinky like anaerobic tea), and is very beneficial for soil organisms and as a foliar spray.

3. FERMENTED, WITHOUT AERATION (do not use). When left in a container for several days without aeration, anaerobic bacteria and fungi chemically alter the mixture into a stinky brew. Some microorganisms in the smelly tea may produce alcohol as a byproduct, which can be highly damaging to plant tissues even in small quantities. Therefore, tea fermented without aeration (or that smells bad) probably should never be used or applied to plants.