Flood Impacts on Food Safety in Gardens

In the aftermath of heavy rains and flooding, it's crucial to be aware of the potential food safety risks associated with contaminated produce and flood-affected gardens.

Floodwater can come into contact with sources of human pathogens and hazardous chemicals, such as raw sewage overflow, farm and domestic animal waste, river or pond water, compost piles, and agricultural run-off. This contaminated water can lead to cross-contamination of produce, food, surfaces, and even gardeners, posing a significant risk to health.

One way to prevent direct contact of floodwater with fruits and vegetables is by raising the soil level using raised beds. Raised beds should be 18 to 36 inches tall and filled with a mixture of peat moss, compost, and clean soil to optimize drainage. This approach not only helps in preventing contamination but also offers several other benefits, such as preventing soil compaction and erosion, improving soil drainage, and serving as barriers to pests like small animals, slugs, and snails. A resource on building a raised bed can be found in the fact sheet "Home Garden Series-Raised Beds."

If produce has come into direct contact with floodwater, the most conservative approach is to destroy it. However, for produce that has had indirect contact, it's recommended to wait 72 hours before harvesting, then thoroughly clean and cook the product before eating it.

Plants with fruit that have not fully matured or ripened at the time of flooding present an unknown food safety risk in terms of foodborne pathogens. Root and tuber crops such as carrots, beets, onions, and radishes should not be consumed raw, whether exposed directly or indirectly to floodwater.

Several crops present a higher food safety risk than others, such as leafy greens, berries, other soft fruits, and cantaloupe. The recommendations for handling vegetables contaminated by floodwater were published by the German Federal Institute for Risk Assessment (Bundesinstitut für Risikobewertung, BfR).

Gardeners and others who mishandle and/or consume fresh produce exposed to floodwater are at risk of gastrointestinal illnesses, such as vomiting, stomach cramps, and diarrhea. To minimize the potential of product re-exposure by contaminated soil, do not replant into soil for 2-3 months.

For disinfecting gardening tools, a resource is available from the University of Florida-IFAS Extension. The URL for the resource is gardeningsolutions.ifas.ufl.edu/care/tools-and-equipment/disinfecting-tools.html. Washing hands with soap and water for at least 30 seconds, drying with a disposable paper towel, and sanitizing garden tools with disinfectants such as Lysol, diluted bleach, or rubbing alcohol can prevent cross-contamination and plant diseases.

Prolonged exposure of plants to floodwater can deprive roots of oxygen, causing plants to suffocate and die. Several days of flooding can cause rapid rotting and death in vegetables and other tender plants. If a garden has been exposed to floodwater, human and foodborne pathogens such as norovirus, Salmonella, pathogenic E. coli, Hepatitis A, Giardia, and Cryptosporidium may be introduced into the garden.

In conclusion, it's essential to take necessary precautions to ensure the safety of produce and gardens following flood events. By following these guidelines, gardeners can help protect themselves and their crops from potential contamination and foodborne illnesses.