Managing Whitetop by Todd Hagenbuch

Have you noticed that the hillsides in Routt County have turned white again? No, Old Man Winter has not returned. What you’re seeing is the bloom of hoary cress, or ‘whitetop,’ one of Routt County’s most aggressive noxious weeds. Two years ago I wrote an article about this nasty actor, but given the unbelievable amount of it I continue to see, it seems necessary to remind everyone why it’s so important to control this plant.   Whitetop is a deep-rooted perennial that grows as much as 2 feet tall and reproduces from root segments and seed. The leaves are a blue-green or dull, gray-green color and are lance-shaped. When blooming, the plants have white flowers with four petals arranged in an umbel shape, giving the plant a white, flat-topped appearance. Plants emerge in very early spring and bloom and set seed quickly, as evidenced this year. A perennial weed, whitetop is common on alkaline, disturbed soils and is highly competitive with other species once it becomes established. It oft