Consider Safety with Flooded Garden Produce

Consider Safety with Flooded Garden Produce

Updated by Connee Wheeler, Senior Extension Associate, University of Kentucky, 2015

It seems we have experienced flooding this summer that has impacted nearly every county in the state. These floods have raised questions on how to deal with vegetable gardens that have been covered with flood water.  The following information was gathered from the University of Kentucky’s Dr. Sandra Bastin, Extension Food and Nutrition Specialist; Dr. John Strang, UK Extension Fruit and Vegetable Specialist; and from University of Michigan Cooperative Extension.

The first consideration for the gardener would be the source of the flood waters. Rain water or water from a potable water source, or uncontaminated source does not carry the same potential hazards as water from a river, septic field or other potentially contaminated source.

Water from floods can be contaminated with sewage or industrial pollutants. Raw sewage contains bacteria that can cause illness if contaminated fruit or vegetables are eaten. Flood waters that cover roads, vehicles, dumps or pass by factories and other manufacturing and business sites can carry heavy metals and other industrial contaminants.

Flood water may be contaminated with sewage, animal waste, heavy metals, pathogenic microorganisms or other contaminants.  These contaminants are deposited not only on the surface of the flooded fruits and vegetables, but may move into plant tissues.  These contaminants can also be present and may persist in the soil after flooding.

The Food and Drug Administration considers these contaminated products “adulterated” and not fit for consumption.  Pooled or standing water after a rainfall that is not likely to be contaminated should not be considered flooding. 

If there’s a doubt then don’t eat!

The most conservative and safe answer to the question regarding consumption of vegetables that have been in a flooded location is, “DON’T.” If you have any doubts or concerns, it is best to discard the vegetables.  Washing sometimes cannot remove these harmful pathogens and contaminants from fresh produce.  It is always the best practice to be safe than sorry.

Fresh fruits and vegetables that have been partially or completely submerged in flood water or that might have come in contact with contaminated water are just not safe to consume.  There is a high health risk of developing disease from consuming these products.

This would include vegetables that are ready to eat in our gardens now.  Also any root crop such as radishes, onions, garlic, beets and/or carrots would be included.

Vegetables that are eaten as stems or leaves, such as asparagus, rhubarb, Swiss chard and herbs would also be considered unsafe if flooded.  Perennial vegetable plants, such as asparagus and rhubarb, can be kept for production next year.  Do not eat them this season, if they came in contact with flood waters.

Also included in the non-edible list are vegetables and fruits that have very tiny, undeveloped fruits already on the vine, such as peas, strawberries, and possibly tomatoes if you bought some plants very early that were started in a greenhouse. You should remove these tiny fruits and any flowers that are on the plants now and not allow them to develop to an edible stage.

Vegetables that result from flowers produced on growth that develops after flood waters subside may be OK to eat.  That could include plants that you may already have planted, but have yet to bloom and set fruit. However, there is some evidence that disease pathogens can be found in plant tissue when these come in contact with contaminated sources, such as in flood waters.

Wash and peel first

To increase the safety for consumption of any vegetables that were grown in or near a flooded garden site this season, wash them well and peel them, if possible. Cook the vegetables thoroughly before eating to increase the level of safety. This could include tomatoes, peppers, eggplants, sweet corn, squash, cucumbers and similar vegetables.

Examine produce from previously flooded gardens carefully before picking it. If it is soft or cracked, or has open fissures where contamination might have entered at any point in time, even after the flood event, throw it out. Produce from plants that survive flooding with water that was not contaminated should also be discarded if they are bruised, cracked, or otherwise blemished.

Contaminated plants and produce from gardens can be tilled under or composted, using good composting methods.  Be sure the compost pile is turned and proper temperatures are reached to kill any pathogens. Contact the Extension Office for additional composting information.

If your produce was in close proximity to a flooded area but did not come in contact with the flood water, prevent cross contamination by keeping harvesting or cleaning equipment and people away from the flooded area during growth and harvest.  Clean well any equipment and tools used in the flooded field. Workers should wear protective clothing such as rubber boots and rubber gloves when working in the field and with plants that may be contaminated. These items should be thoroughly scrubbed and cleaned after working. 

If an unplanted field has been partially or completely flooded, determine the source of flood water and determine whether there are significant threats to human health from potential contaminates in the water.  Allow soils to dry sufficiently and rework the soil, before planting crops.  Adding compost or other organic matter when tilling will be beneficial to the soil.  We are still early enough in the growing season that new vegetable plants can be planted and some crops can be grown for fall harvest.

Replanting a flooded garden

When planting new gardens that have been covered with considerable floodwater soils that have been covered with floodwaters should be tilled at least six inches deep after they have dried out before planting a new crop. Standard soil tests done through the Extension Office will not be able to tell you if there are contaminates in your soil. These tests are for plant nutrient levels only. 

Any gardens that were covered with contaminated flood waters can be assumed to be contaminated with harmful pathogens, so special testing for this is not necessary. With rain and sunshine, the levels of the pathogens will disperse. After the first good rain, research shows that the majority of harmful pathogens are removed from the surface.

Since there are many bacteria, good and bad, normally present in the soil, but need other factors for growth, this is adequate for human safety levels. If you are still concerned, use rubber gloves to garden with and wash all fruits and vegetables well before consuming.

Produce from flood-damaged gardens should not be sold, given away or consumed until the risk of contamination is gone.  Produce should also not be used for home canning, freezing or used with other food preservation methods.

As always, proper food handling methods in the kitchen are important for food safety.  They include, washing hands while preparing food, cleaning and disinfecting work surfaces, equipment and supplies, use potable water and “if in doubt, throw it out”.

Contact your local Extension Office for additional information and answers to other food and gardening questions.

Original Article Published: May 7, 2010 by Kim Coward (former Franklin County Extension Agent) in The State Journal of Frankfort, KY - http://m.state-journal.com/spectrum/2010/05/07/horticulture-news-my-garden-s-flooded-now-what-do-i-do.