Posted by: Carol O'Meara, Horticulture Entomologist, Boulder County Extension
UPDATED: September 19, 2013
If you’re cleaning up your vegetable garden after the flood waters
recede, consider the safety of eating produce from the garden. If rain, and only rain, fell on the garden
everything is fine, but if it was touched by or near flood water, your produce
is risky-to-dangerous to consume.
Flood waters can contain sewage, pollutants such as oil, gasoline,
solvents, etc., bacteria and parasites such as Giardia, Cryptosporidium, E. coli, Shigella, Hepatitis A, and a
host of other unsavory contaminants.
Young children, seniors, pregnant women, and people with compromised
immune systems are at highest risk for serious effects from consuming
contaminated food and should not eat any produce that was in or near
floodwater.
In every case where the edible portion of the plant came into
contact with flood water – submerged or splashed - there is risk, regardless of
whether it is above or below ground. In
many cases, there is no effective way for washing the contaminants off of the
produce.
To help you sort through what to do for crops that were near to
flood waters, here are quick tips:
All crops eaten raw should be discarded, such as lettuce,
mustards, spinach, cabbage, collards, Swiss chard, arugula, or micro
greens. Soft fruits like strawberries,
raspberries, or blackberries as well as leafy vegetables such as spinach,
chard, beet tops, or kale may be impossible to clean well and must be cooked
before eating; avoid eating them raw.
Because rain or sprinklers can splash contaminated soil back onto these
plants and contaminants can become embedded in the leaves, stems, petioles,
etc., the area is not safe for growing for 90 days, minimum.
Root crops, including carrots, radishes, parsnips, beets, or potatoes should be washed
and rinsed in clean, potable (safe for drinking) water, sanitized in a dilute
bleach solution, and then rinsed in potable water. They should also be peeled and cooked before
consuming.
Make your sanitizing solution by mixing a scant tablespoon of food
grade bleach, without fragrances or thickeners, to one gallon of potable
water. Wash the produce with clean,
potable water, using a vegetable brush to clean in crevices. Rinse, then dip into the sanitizing solution
for two minutes, then rinse in clean water.
Peas, beans, tomatoes, peppers, eggplant, summer squash and other
soft skinned crops that are present during the flood should be discarded. Winter squash, winter melons, and pumpkins,
with their thick rinds, can be washed and rinsed in potable water, then
sanitized in the dilute bleach solution described for root crops, and rinsed.
Questions on stage of plant growth versus potential for
contamination can be summed up in this very good Purdue University response
from Liz Maynard, Regional Extension Specialist, Commercial Vegetable and
Floriculture Crops: “Risks can be described as follows:
•Edible portion of crop present: Very High Risk. Fresh produce is considered adulterated.
•Plant emerged, edible portion not present: High Risk. The potential presence of microorganisms in
the plant as well as in the soil could result in indirect contamination of the
crop post flooding (splashing onto plant, etc.).
•Planted but not emerged: Still High Risk for reasons given above
from post flooding contamination in soil.
•Pre-planting: Moderate Risk.
Soil contamination may be as dangerous as that of uncomposted
manure. Tilling in the soil and a minimum of 90 days between the recession of
waters and harvest are needed to reduce this risk from pathogens, but
recovering soil from chemical pollutants may take longer.
To protect crops and
areas not directly touched by flood water, wash your hands before and after
you’re in the garden, leave your garden shoes just outside your door, and
change out of clothing you wore to work the vegetable patch.
