By: Diane Wright Hirsch, MPH
Extension Educator/Food Safety
Over the weekend, before the most recent snow, I looked out my kitchen window to see my dog squatting over the chive patch in our vegetable garden. It was too late to stop him.
I spend a lot of time with Connecticut farmers, talking about producing safe fruits and vegetables. We always talk about how animal feces can affect food safety. Animals and birds are often the source human pathogens or microorganisms that can make us sick. Some examples of those pathogens include E. coli O157:H7 (associated with many outbreaks tied to meat, poultry and fresh produce, most recently lettuce); Salmonella (eggs, poultry, pork, sprouts, cucumbers and cantaloupe); and Listeria monocytogenes (all types of foods, including processed meats, cheese, cantaloupe, apples, and frozen vegetables).
Wildlife can spread human pathogens by depositing feces in fields or water sources and spreading fecal contamination as they move. This is very difficult to control. Complete exclusion may not be possible, depending on the species of wildlife. It can be a tough job for farmers to exert any kind of control over geese, other birds, deer, or rodents.
Generally speaking, a home garden is a more manageable space. There are things you can do to discourage the presence of wildlife, though nothing is fail-proof. The first thing you may have to do is to identify the pest. Once you know which animal is eating the lettuce or leaving droppings around, knowledge of their habits and food needs can help you choose the best method to deter them. The University of Connecticut www.ladybug.uconn.edu site has fact sheets that give advice regarding control of wildlife in your yard. In addition, take a look at http://npic.orst.edu/pest/wildyard.html for additional suggestions on specific species.
Here are some suggestions that may help:
- Fence your garden. Fences can make for good neighbors, they say, and this is certainly true of fences that keep animals away from your tomatoes. The fence can be as simple as a strong wire mesh. You may have to bury the fence several inches into the ground to prevent creatures from burrowing under the fence. Some animals are perfectly capable of climbing the fence to get to the other side (did someone say, “squirrel”?). A metal shield at the top of the fence might be useful.
- Be careful where you hang your bird feeders/houses/bird baths. If birds are feeding or nesting at the bird feeders or houses you have purposely added to your yard, they will be more than happy to poop on your plants as they fly back and forth. This is a lesson easily learned as our birdhouse attracts lots of birds and their droppings on our patio furniture and patio tomatoes alike.
In addition, do not let garden trash build up—dropped fruit and pulled weeds can feed and shelter small animals. Cover trashcans, compost bins and other potential sources of food. Remove pet food or birdseed from the yard.
- Use decoys or other deterrents. While these can be effective on a variety of wildlife, it is important to move the decoys every few days. Deer, birds and rodents may be smarter than the average bear: they can figure out when a fake coyote is fake.
One of the most difficult “pests” in the backyard vegetable garden can be Fido or Fluffy—resident dogs and cats. Fencing is most likely to help keep the dog away. Of course, you need to remember to close the gate. An open gate turned out to be how my dog got into the chive patch.
Cats love the soft soil of a garden and WILL use it as a litter box. Of course, the best course of action is not to let your cat out at all. There are too many ways they can get injured, sick, or worse whether you live in a city, suburb, or on acres of land.
If the dog gets through the gate or over the fence and poops on your edibles, there is little you can do. If it is early in the season and the plant has no edible parts, you can wait 120 days to harvest, treating the feces like raw manure—feces from another species. If harvestable or close to harvestable produce is affected, it is best to leave it on the plant. Do not harvest, do not eat; do not harvest, wash and eat. It is just too risky.
This would be true if you see signs that indicate the presence of other wildlife as well. Bird poop on the tomatoes or lettuce leaves; mouse droppings in the herb bed; or evidence that rabbits have been gnawing on the cucumbers. You really should not eat any fruits or vegetables that have been pooped upon. Washing is not necessarily going to totally eliminate any risk from human pathogens that might have been left behind. Do not toss affected produce in the compost bin either. Animal feces should never be added to compost that will be used on edible plants.
This advice is especially important if you have kids, seniors or others in your family who might have a compromised immune system. It is just not worth the risk.
For more information about food safety and controlling wildlife in your back yard, visit our website at www.foodsafety.uconn.edu, check out some of the links in the article, or contact the Home and Garden Education Center at firstname.lastname@example.org or 1-877-486-6271.