No, I'm not talking about your brother-in-law. Thickhead or redflower ragleaf (Crassocephalum crepidioides) is an introduced weed that I'm observing with more frequency in nursery and garden centers in North Carolina The species is much more common in the Gulf Coast states and is spreading to other regions in contaminated nursery stock. When vegetative, the plants strongly resemble our native American burnweed (Erechtites hieraciifolius), but has very distinctive drooping, salmon-red flower heads. In contrast, American burnweed flowers are upright and creamy-white. Thickhead seeds are wind-dispersed and germinate anytime from spring through late summer. In container nurseries it can be controlled with preemergence herbicides containing dimethenamid-p, flumioxazin, indaziflam, or oxyfluorfen. In landscape plantings, prevent plants from going to seed and apply a fresh layer of mulch. For more information about this and other weeds of landscapes and nurseries, check out the information on my portal: Weed Management in Nurseries, Landscapes and Christmas Trees.
Have You Seen Thickhead in Your Garden?