Area Extension Agronomist Whitetop is a deep rooted creeping perennial mustard plant that grows up to 2 feet tall, reproducing from root segments and seeds. Leaves are blue-green in color with the lower leaves being stalked and the upper leaves having two lobes clasping the stem. Plants have many white flowers with four petals, giving the plant a white, flat-topped appearance.
Plants emerge in very early spring and have bloomed and set seed by early to mid-summer.
Whitetop is a very aggressive plant that will eventually eliminate desirable vegetation. The plant is common on alkaline and disturbed soils. Whitetop can be effectively controlled with properly applied herbicides. The product choice and stage of application is important in achieving acceptable control. However, one application of any herbicide will not completely eliminate whitetop as is the case with most perennial weeds.