As the main stem of the plant starts to shoot up, or bolt it can grow to be 1 to 3 feet tall. The plant has a deep taproot. Flowers are generally white, but sometimes pink or lavender. Diffuse knapweed can produce up to 1,200 seeds per flower stock. This assists the plant in taking over lands very quickly.
Upright stems have numerous spreading branches, and a tumbleweed mobility when broken off.
Mature plants are easily caught and transported on all types of farm, ranch, and recreation vehicles. This is commonly the plant you will see being carried along roads on the undercarriage of cars and trucks. The key to managing knapweeds is early detection and treatment of invading plants. A combination of control measures works best for long-term control. Reseeding with productive forages, hand-pulling, mowing to reduce seed production, and herbicides can be used to assist in management of knapweed.