Food safety should be a serious consideration for everyone but is particularly important for those at greatest risk of food-borne illnesses, including young children, the elderly, pregnant women and those with compromised immune systems. Flood waters many be contaminated by any combination of sewage, river or creek water, farm run-off or industrial pollutants. Bacteria, parasites, viruses and chemical contaminants are the biggest concerns to food safety.
What fruit or vegetable produce can gardeners safely use following a flood? The most conservative answer - one that eliminates all risk - is all produce touched by flood waters should be discarded.
However, when a flood occurs early in the growing season there may be weeks or months of growing season left. Can any produce be salvaged? Below are tips to help you determine what can be harvested and how to handle it to reduce food safety concerns.
National Organic Program (NOP) Guidance
NOP outlines requirements for growers using fresh manure as a soil amendment and fertilizer to reduce potential contamination to food crops grown in that soil. It estimates a timeline for microbial die-off, if contamination did occur, to ensure food safety. Fresh manure is considered a greater contamination risk than flood waters, so similar guidelines could be used by gardeners dealing with flooded garden produce.
When flooding occurs during the growing season, all produce present at the time of the flood and touched by flood waters should be discarded.
If the edible portion of the crop WAS NOT PRESENT at the time of flooding, then you may be able to harvest produce which appears later on surviving plants. The first consideration is whether the edible portion of the crop grows in direct contact with the soil or not. Use the following guidelines.
- Edible portion of crop NOT in direct contact with soil, like tomatoes, peppers or sweet corn – allow at least 90-days from the flood event before harvesting any produce
- Edible portion of crop in direct contact with soil, like cucumber or potatoes - allow at least 120-days from the flood event before harvesting any produce
Harvesting & Handling Tips
Here are additional tips and guidelines to help determine what should be harvested and how best to handle it to reduce food safety risks.
- Discard all leafy greens. All lettuce, spinach and other greens touched by flood waters should be discarded. Their leaves contain too many ridges and crevices that can be contaminated, and cannot be adequately cleaned. Fortunately, these crops grow quickly and a new crop can be grown from seed in a fairly short time. To be extra careful, plant the new crop in ground not contaminated by the flood.
- Will the produce be eaten raw? If the answer is yes, discard any produce that came in direct contact with flood waters and is normally, or frequently, eaten raw. This includes strawberries, raspberries, melons, onions, carrots, etc.
- Underground vegetables. Root crops, such as beets, carrots and potatoes, that are still early in their growth with at least 4-8 weeks before harvest should be safe if allowed to grow to maturity and cooked before eating. Root crops that will be harvested within a month after the flood, such as new potatoes, should be washed, rinsed and sanitized as outlined below, before cooking thoroughly.
- Clean the produce. Early season crops present during the flood, such as tomatoes or peppers, that where not touched or splashed by flood waters and which will be harvested a few weeks after the flood event, should be safe to use if cleaned, and cooked or peeled.
- Discard any that are soft, cracked, bruised or have open fissures where contamination might have entered.
- Fresh fruits and vegetable should always be washed before eating, by rinsing it under tap water and with the friction of hands to remove dirt and debris.
- Do not use soap, detergents or bleach in the washing process. Produce is porous and can absorb these chemicals.
- Remember, if garden produce was touched by flood waters, it is unsafe to eat. Don’t attempt to make contaminated produce safe by using a fruit and vegetable spray, chlorine bleach, or other cleaning product.
- Late season vegetables. Fruits developing from flowers produced after the flood waters subsided should be safe to eat. This includes tomatoes, peppers, eggplant, squash, cucumbers and similar vegetables. Be sure to wash produce thoroughly before use and consider using them in recipes that are cooked to further reduce food safety risk.
One final thought - pooling of water from excess rain, but not contaminated by outside water sources like a creek, stream or livestock area, is not considered flood waters.
For more information on flooding and produce safety, visit Flooded Gardens and Crops from Cornell University.
