By William H. McCaleb
Program Assistant for Agriculture & Natural Resources
Virginia Cooperative Extension
As we are all dealing with physical distancing daily with the COVID-19 virus, gardeners know about prevention of diseases in summer vegetables. Gardeners know that one infected plant can be the carrier of a pathogen to other plants. Some do it by close proximity to each other when we plant certain varieties too close to each other, others through interlaced roots. One example is the German Johnson tomato, one of our most popular heirloom tomatoes. The fruit of this plant is probably one of the most full-flavored tomatoes you will find at the Farmers’ Markets or roadside stands. This heirloom tomato is seldom found in a grocery store because they have a short shelf life and don’t ship easily. But, oh how good when you can pick them, wash them off, and proceed into the kitchen for that sharp knife, grab a loaf of bread and your favorite mayonnaise, and yes, you need a wee bit of salt and pepper to make it so perfect. The perfect sandwich coming right up!
German Johnson is an heirloom tomato variety which is prone to disease. It is worth the extra effort for the delicious flavor on a ‘mater sandwich.
You will find larger tomatoes with longer shelf life, but people who grow the German Johnson tomato, know it is susceptible to several diseases and they do their level best to plant them far enough apart, at least three feet, to avoid the pathogens that cause early blight and leaf spot. The German Johnson tomato did not originate in Germany, as far as I know. It is an Heirloom that the Mennonites discovered over 50 years ago. Some in North Carolina claim that fame, and some in Eastern Tennessee and a couple of other states make the claim. The main thing is we get to plant and eat these wonderful heirlooms. Needless to say, if you grow them, you will want to save some of the seed for the next year. Yes, the seed will yield a true German Johnson again next year, unlike most of your hybrid varieties seeds.
Let’s get back to the similarity between growing susceptible tomatoes and dealing with the unknowns of the COVID-19 virus. In both cases, sanitation and prevention is an absolute. With COVID, you need to constantly be aware of the surfaces that you touch and then “wash your hands” properly often to avoid spreading the viral pathogen. With the tomatoes you need to be aware of the fastest way some fungal diseases are spread, by raindrops that hit the dry soil and splash particles upwards to the underside of the plants. We know that the pathogen that causes Early Blight is soil borne. Like COVID that affects humans, (it has been found in cats like the tigers and also a dog or 2). the pathogen that causes Early Blight won’t bother many of your other garden plants, just those in the nightshade (Solanaceae) family. That would include your potatoes, peppers, and eggplant as well, just to name a few. Don’t worry about your cucumbers, salad greens, or root crops like radishes and turnips. They aren’t bothered with this pathogen and have enough insect pressure as many gardeners know.
Once the lower leaves of the tomato plants become infected, the first thing you will notice is some light discoloration and leaf spots. Soon those lower leaves drop off the plant. This debris drops to the ground and if you don’t use good sanitation and pick up and clean up around your plants, the pathogen becomes more active producing multiple amounts of fungal spores, especially when we get rain and the soil remains between 60 - 82°F. With a three-foot distance between each plant, that is the minimum distance you want to keep the plant at ‘top health’ as it is growing and producing. Any closer and you don’t get the airflow, necessary moisture for the roots, and sunlight around each vine to make them happy. Likewise, the scientists have determined to keep you healthy and safe during this COVID 19 onslaught, they say six feet is the closest distance you should be from the next person. More space is better when it comes to planting vegetables i.e. 4’ distance is better than 3’; 10 feet might be better distancing between people when they are gathered together while COVID is with us. I don’t know and don’t have any scientific data to back up that statement outside of just good old common sense.
Gardening experience has shown me over the years that when you can keep a plant healthy and strong, it will resist diseases better than one that is stressed. If you maintain a schedule of checking your plants (scouting) daily for signs of stress or damage, you have a better chance of saving a crop. When you do find signs or signals of stress or damage, there are several good fungicides on the market that will help prevent some of the diseases related to tomatoes. If you catch it quickly and use either an organic or other fungicide you are more likely to be enjoying good tomatoes right up until frost. With COVID, I think if we all can put out that extra effort and wear a mask and keep our distance, we’ll all be around next year to enjoy that wonderfully delicious German Johnson tomato. Maybe someone should look into this potential cure; to eat plenty of tomatoes, tomato sandwiches, stewed tomatoes, tomatoes and okra, and as we used to say in Alabama, forty-eleven other ways to prepare them. Now I’m getting hungry.
While we are all still practicing ‘physical/social distancing’ due to COVID-19, and all Halifax County buildings are closed to the public, if you have tomato or gardening questions, you can best reach an Extension Master Gardener or Extension staff member by sending an email to firstname.lastname@example.org or email@example.com. If you can’t email, you can call and leave a message at the Extension Master Gardener Help Desk at 434-830-3383, giving us your name, telephone number, and nature of the call. The Help Desk phone is checked timely and someone will get back to you, although it may be from a different telephone number.