A. Mark Renz, UW-Extension weed scientist at UW-Madison's department of agronomy, said varying environmental conditions ensure that virtually all plants, including dandelions, have some good years and some poor ones.

But he said dandelions seem perfectly suited to conditions in this area.

"I've only been in Wisconsin for two years, but I am amazed at how common dandelions are," Renz said. "I have never lived in a place where the environmental conditions are just right for dandelions to explode like this in the spring."

Dandelion seeds can drift on a breeze of just 4 mph, and the plants can live for several years, so they can survive poor years and jump up the next spring.

The ecological role of weeds is to occupy new ground, and dandelions "are really good at invading sites," Renz said. "Wherever they land, if there is bare ground, when it warms up, they will start germinating."

In some years, dandelions have sprouted by February or March, he said.

The bad news is that an acre of pure dandelions can produce about 250 million seeds, Renz said. The good news is that, "in the grand scheme of things, there are a lot worse plants than dandelions."

— Produced in cooperation with University Communications

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