Verticillium Wilt

Verticillium albo-atrum or Verticillium dahliae, two closely related fungi.

Sunflowers with verticillium wilt
Sunflowers with verticillium wilt [Credit: Howard F. Schwartz]
Verticilium wilt on sunflower
Verticilium wilt on sunflower [Credit: Howard F. Schwartz]

Host Plants:

On Crops: Tomato, potato, and numerous flowers

Where Found:

Cool temperate climates worldwide


Plants grow normally until midsummer, when they begin to wilt, but do not turn yellow as they do when infected with fusarium wilt. Plants stricken with verticillium wilt appear droopier each day, with some branches more wilted than others, and make no new growth. Ultimately infected plants melt into a heap of wilted foliage and die. Often plants growing next to each other are infected but others growing close by remain healthy.


Following a cool, soaking rain, with temperatures around 70F (21C), verticillium fungi enter the roots of susceptible plants, multiply, and clog up their vascular systems. Any fruits that do ripen are not likely to taste good because of the nutritional and moisture stress caused by this disease.

Preventing Problems:

Grow resistant varieties if verticillium is known to be present in soils in your area. If you want to grow susceptible heirloom varieties, grow them in containers filled with bagged soil.

Managing Outbreaks:

Pull up infected plants discard them in the trash, or in a very active compost pile.

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