Question From: A. Redd - MICHIGAN
Q: A few weeks ago you wrote a recipe that you use to keep your tomatoe plants healthy and desease free. I lost that article. Can you post the recipe here. We tried container tomatoes and the bottom leaves are brown, the fruit has blossom rot, help?
A: Your blackened bottoms and brown leaves are the fault of lack of water. In hot dry weather calcium is unable move through the plant and the result is blossom end rot. Container tomatoes need watering twice a day in this hot dry weather. My recipe will not make up for lack of water. Your brown leaves at the bottom of the plants are old and warn out. Remove any leaves that are discolored as soon as they appear. Diseased leaves have lesions, spots and other markings. You don't usually get diseases in containers. According to Michigan State University Extension we may be in for another tough tomato season. After weeks of cold wet weather, the forecast calls for warm nights with high humidity and that’s the perfect recipe for fungal diseases. At dinner last week my brother brought up the subject of using aspirin to stimulate ‘Systemic Acquired Resistance’, often called SAR, in tomato plants which I have written about before. Researchers at the USDA and the University of Florida found the active ingredient in aspirin, salicylic acid, will activate and boost a plant’s SAR against bacterial, fungal and viral diseases. When sprayed with a mixture of 1 and ½ 325 mg aspirins dissolved in 2 gallons of water to which 2 tablespoons of mild dish soap has been added to act as a spreader sticker every 3 weeks, it not only improved the plant’s resistance to disease, it also improved growth, increased fruit size and production. This recipe can also be used on peppers. Do remember that more is not better as far as number of applications or aspirins used. Too much salicylic acid can damage the plants. When using foliar sprays remember to apply them in the morning or in the evening when the sun is going down, so as not to burn the leaves. And, cover the entire surface of the leaves including the undersides. Other methods of protecting tomatoes from soil borne diseases including early blight, is to create a soil barrier to prevent spores from splashing on the plants. Begin by pruning the lower leaves of the plant. I prune up about six inches. Then cover the surface of the soil with four sheets of newsprint taking care to overlap so the area stays completely covered. Dampen the paper and pat it in place so no air pockets remain. Mulch the surface of the paper to hold it in place. One gardener recommended using course sand or small pebbles that will help keep everything in place and prevent moisture from building up around the base of the plant. In late fall the sand can be turned into the soil or shoveled onto pathways. As the season passes and the tomato plants grow, removing the suckers that sprout between the stem and leaf branch when they are small will help to increase airflow around the plant and prevent shading. This also helps deter disease. Google “how to prune tomatoes’’ and you will find all kinds of pictorials that take the mystery out of this job.