Is It Safe to Use Humanure Compost on Fruit Plants?

Pathogen Destruction and Weed Seeds

Humanure composting is a process that breaks down human waste into a stable, nutrient-rich fertilizer. However, if not done correctly, humanure can contain pathogens like E. coli and Salmonella that can harm plants and humans. To ensure pathogen destruction, humanure composting requires a minimum of 6 months of aerobic composting at temperatures above 131°F (55°C). Additionally, a 2:1 ratio of “brown” materials (e.g., wood chips, straw) to “green” materials (e.g., humanure, food scraps) is recommended to facilitate decomposition. This ratio can be adjusted based on the moisture content and carbon-to-nitrogen ratio of the compost pile.

Application and Dosage

Once humanure compost is pathogen-free and weed-seed-free, it can be safely applied to fruit plants. A general rule of thumb is to use 1-2 inches (2.5-5 cm) of compost as a mulch around the base of the plants. This will provide a slow release of nutrients and improve soil structure. It’s essential to avoid over-fertilization, as humanure compost is high in nitrogen and can cause excessive vegetative growth and reduce fruit production. A moderate application of 1/4 to 1/2 cup of compost per plant, depending on plant size and growth rate, is recommended.

Fruit Plant Selection and Precautions

Some fruit plants, like strawberries and blueberries, are more susceptible to humanure-borne pathogens than others. To minimize risks, choose fruit plants that are more resilient to disease and pests. Additionally, avoid applying humanure compost to fruit plants that are under stress or have existing health issues. Finally, always wash hands and utensils thoroughly before and after handling humanure compost to prevent cross-contamination.