How to Avoid or Control Tomato Blight

Published on
July 8, 2023 at 1:58:00 PM PDT July 8, 2023 at 1:58:00 PM PDTth, July 8, 2023 at 1:58:00 PM PDT

To most people, tomato blight refers to a number of specific diseases that can attack tomato plants. These diseases are usually soil-borne.


This means they survive as spores in the soil, and then make their way to the leaves of the plant during the summer, mainly from splashing water. Some types of blight are treatable when caught early. Others are difficult to control, like Septoria leaf spot.


Some cultural practices that can help you avoid tomato blight and other diseases are as follows:


  • Rotate crops, tomatoes should not be grown in the same location every year.


  • Plant tomatoes three feet apart for good air circulation.


  • Use tomato cages to help keep foliage off the ground.


  • In early June, cover the soil around the base of the tomato with a thick layer of straw, or wood mulch. This prevents spores from splashing up from the soil and landing on the foliage.


  • Water at the base of plants and avoid overhead watering.


  • Work the plants when the foliage is dry.


  • If a plant gets blight, remove the lower affected leaves and discard in the trash, not the compost bin.


  • Remove all plant debris in the fall.


Most folks choose to follow this rule when it comes to tomatoes with blight - If one tomato plant has blight, it can spread to other plants, so treat all the tomato plants. Of course you can choose to only treat the plants that you see are affected by blight.


Earl May Fungonil Disease Control is a great product to help control tomato blight and other diseases. Fungonil is available in several variations including ready-to-spray and concentrate, plus it can be used close to the day of harvest, see label directions.


Visit your local Earl May Garden Center for more information on tomato blight. Visit our blog post more tips on growing the best tomatoes.