Fresh Farmyard Manure & E.Coli

I managed to tear myself away from workshop planning the other night and switched on the TV for an episode of CSI Miami. I was immediately reminded about an article I’d read in the February edition of Gardeners World a few weeks ago about E.coli. (Just can’t get away from work sometimes – just as well I love my subject!)

It particularly rang alarm bells in my head as I’d mistakenly thought that because we don’t spray our vegetables with insecticides, they were safe to eat straight from the garden (the children have always picked or pulled veg straight from the plants, brushed off the dirt and eaten them).

Escherichia coli (E. coli) is the name given to a large family of bacteria commonly found in the gut of humans and animals. Whilst the majority of E.coli are harmless, some types can cause illness. The E. coli O157:H7 strain causes serious illness in humans ranging from diarrhoea to kidney failure, and even death.

Cattle are the principal source of this strain. It’s also present in the intestines of other animals including sheep, goats, deer, horses, dogs and cats. Seagulls, pigeons and geese are also known to carry the organism.

Whilst most people get E. coli from contaminated food (such as under-cooked minced beef), it also can be passed in the manure of cattle. Animals do not have to be ill transmit E. coli O157 to humans.

For those of us who use cattle manure as a means of incorporating organic matter into our vegetable gardens, Bunny Guinness, commenting in the Gardeners World magazine, recommended the following:

Fresh farmyard manure should never be used directly on vegetable gardens. It should always be left to compost for at least a year, turned regularly to encourage high temperatures and left to ‘cure’ for two to four months. This should allow the beneficial bacteria to kill the disease-causing ones. You must then leave at least 120 days between applying the composted manure and harvesting the crop – 90 days if the crop is protected by a husk, shell or pod.

Always wash hands well after handling manure, and maybe even your tools, boots and clothes. Wash the vegetables thoroughly before eating.

With hard-to-clean- crops like lettuces, especially if they’ll be eaten by vulnerable people (pregnant women, the young or elderly), consider using one to three teaspoons of chlorine bleach per gallon of water, then rinse well.

We’ve been warned!