Q: This summer I added quite a bit of composted horse manure (from a local stable) to the soil of my vegetable garden.
With the concerns about E. coli in the soil, do you think that it is safe to plant my fall vegetables in this soil?? I regularly plant lettuces, carrots, beets and other root vegetables.
A: I grew up eating vegetables produced in a garden located directly between two large, open chicken houses. During that entire time I can not remember any illness attributed to the vegetables we ate among the five children and two adults in my family.
Remember that the particular E.coli associated with human disease outbreaks is just one of hundreds of strains of this bacteria. Most are harmless; some are necessary for good digestive health.
Composting tends to lower the amount of E. coli in manure but composting does not eliminate it. Mixing the composted manure in the soil lowers E. coli even further but no manure can be considered to be E. coli – free.
Despite that, I think the minute risk of sickness is an acceptable trade-off for the health benefits of fresh vegetables. I’m the living proof of that!
In my opinion, mixing composted manure into the soil before planting does not increase disease risk – particularly if you wash the produce thoroughly before eating.
Does Horse Manure Pose a Significant Risk (scroll down to page 5 for the part about bacteria)