As someone who has been growing edibles for over 30 years, I can tell stories about crop failures and successes of all kinds. But one old reliable has always been tomatoes. Until 2009, that is. One day, all the leaves on my big vines full of fruit, just wilted and turned brown. Tomato Blight had struck!

For all those folks (mostly in the Northeast) who also didn’t have a good tomato crop, the UMass Extension Agriculture Services shared some reliable scientific information about tomato blight. The good news is that it is killed by freezing temperatures and so will not live past winter in snowy areas (except in potato tubers). Phytophthora infestans, or late blight as it is called, does not survive in freezing soil, or on weeds killed by cold.

Normally this fruit “bug” moves up from the south on wind currents and arrives late in the season, causing less damage. In the spring of 2009, it was introduced very early by infected commercial tomato transplants (aka Careless giant commercial growers). Then it spread in June’s wet weather. How bad was it? I was told that two of the biggest commercial tomato farmers in Massachusetts went bankrupt due to the condition of their crop.

How can you prevent future outbreaks? Here are four tips:

  • Clean up the garden carefully over the fall and throw out all black or wilted leaves, fruits, stems and roots.
  • Don’t mulch with any infected plants, flowers, or perennials that look wilted and blackened.
  • Let the ground in next year’s garden freeze over.
  • Rotate crop locations, if possible.

Get more info on the Cornell University Department of Horticulture website.