Disease spreading throughout garden.... again... this happened last year in july

Asked August 22, 2017, 8:13 AM EDT

My cucumber and tomatoe plants began dying at an alarming rate on Saturday. It's been getting progressively worse. This happened last year as well. I planted all disease resistant varieties this year and changed all the soil etc. and rotated the crops. What is going on? Is there any way I can stop it? Please help!!!

Baltimore County Maryland

1 Response

Maryland's warm, humid summer weather is conducive to many plant diseases. The weather patterns for the 2017 growing season have been particularly good for the spread of tomato and cucumber diseases.

This recent post on the MD Grows blog will help you learn more about the principal tomato plant defoliators- Septoria leaf spot and early blight- and how to manage them:
https://marylandgrows.umd.edu/2017/07/21/steps-to-prevent-and-manage-tomato-leaf-spot-diseases/
There are no reliably resistant cultivars to these two fungal diseases.

We can't tell from the photos precisely what is happening with your cuke vines. Some of the more distinctive yellowish lesions could be one or more of many different diseases. Downy mildew is the most serious and can be detected by the mats of light colored fuzzy growth on leaf undersides:
https://extension.umd.edu/growit/downy-mildew-cucurbits-spinach-and-brassicas-vegetables

Other kinds of cultural and environmental problems may also be at play. For example, tomatoes need a minimum of 6-8 hrs. of direct sunlight and cukes need at least 5-6 hrs. jt