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.
Roundup (glyphosate) applied as a 2% solution at the flower stage has resulted in fairly good control. 2,4-D applied at 3 qts/acre 2 to 3 times per year for 3 years has also been somewhat effective. Noncrop herbicides such as Escort and Telar are probably the most effective as long as some rainfall occurs after application to activate the products.
Always read the entire label before using any chemical. For more information contact one of the Tri River Area Cooperative Extension offices (Montrose (970) 249-3935, Delta (970) 874-2195, and Grand Junction (970) 244-1834).
Additional information on the control of this and other weeds is available.
Page developed and maintained by Curtis E. Swift, PhD,