Safety of Produce when Your Backyard Vegetable Garden Floods

This year I got my vegetable garden in early, and by the first days of June was already bringing fresh herbs; parsley, marjoram and mint; as well as lettuce and Swiss chard to the dinner table. Then, disaster struck. Torrential rains caused local flooding. The small spring-fed creek adjacent to my garden transformed briefly into raging mud-colored foul-smelling rapids. While we have this creek excavated every couple of years to deepen it, it had silted in more that we had anticipated and couldn't contain the amount of water forcing its way through.

The rush of water was so strong that it carried with it wood and debris from the farm fields above our land. Then, the water breeched the bank the creek began flooding our yard and my beautiful young garden. The lettuce and Swiss chard were sitting in a pool of brown water, their leaves dipped down into it, having been splayed flat by the same heavy rain that caused the stream to flood. I had a heartsick feeling that my garden had been rendered inedible and even toxic. My research confirmed that I was right.

Gardens can get flooded from several different sources. If they suffer an extremely heavy downpour of rain, or continual days of heavy downpours, plants can become wilted and waterlogged, and small seedlings can be washed away. When the rainy period ends, the water will eventually absorb fully into the earth and the surviving plants may take a number of days to bounce back. A few may have rotted and will need to be discarded. But on the whole, many vegetables will survive, as they naturally thrive on water. The top-most layer of soil may have turned to a hardened crust of mud that can be broken up with a hoe, of simply removed. When flooding is caused by clean rainwater, the vegetables will likely recover well in time and should not be unsafe

However, when gardens are flooded by rural streams and creeks, particularly those which emerge from cow pastures and fields, the situation is quite different. Farm run-off is often toxic. It can carry with it raw cow manure, a prominent source of e-coli and other bacteria, as well as fertilizers, pesticides, fungicides, herbicides and other farm chemicals. Additionally, as these creeks run through rural backyards, they are often the recipients of leech-field run-off from septic systems, another contributor of toxic bacteria.

When gardens are flooded by any body of water which has overflowed, including water from creeks, streams, and gullies, toxic contamination is likely.

According to a 2007 article by Barbara Ingham, Department of Food Science at the University of Wisconsin Extension¹, the safest approach is take absolutely no chances: if farm run-off has flooded your garden, do not eat the produce. Take it as a loss and a lesson and try to re-plant whatever it is possible to grow in the remaining season on a new garden plot.

The article does specifically note that all leafy vegetables and soft fruit such as berries in such a flooded garden must be discarded. But it also gives some very cautious recommendations as to what produce might possibly be saved when it is late in the season and there is not time to re-plant on safer ground.

What did I do? The old adage "when in doubt throw it out," applies here in spades. I took out the lettuce and the chard and tossed them out. I will refrain from using any of the herbs this year, though to keep them from growing out of control, I will continue to weed them, and cut them back. By next year they will be fine.

My local nursery owner assured me that my tomatoes, which had not yet even flowered when the flooding occurred, will apparently be fine-though I will discard any that fall to the ground. Meanwhile, I am planting flowers in this garden plot and moving my vegetable garden to higher ground.

1. kenosha.uwex.edu/flp/documents/SafetyofProducefromFloodedGardens.pdf