RAPID CITY, S.D. (AP) – Two wet growing seasons have fueled runaway sweet clover growth across South Dakota.

The yellow plant is becoming so prolific it’s shading out some native species.

The plant is biennial, which means it has a two-year life cycle. That means it takes a couple of consecutive wet years to produce the wave of growth the state is experiencing.

Krista Ehlert is a range specialist with the South Dakota State University Extension Office. She says the plant spends the first year growing its root system. It turns all its energy to above-ground growth in year two, when it blooms. She says the plan can grow as tall as eight feet and become so tough and stringy cattle can’t eat it and haying equipment can’t cut it.