Description:
Velvetleaf is a summer annual that reproduces by seed. Velvetleaf reaches 3 to 8 feet tall or more, growing from a stout main stem, with upper branching. As the common name implies, the entire plant is velvety and soft and is completely covered with short, fine hairs. The leaf arrangement is alternate. The large heart-shaped leaves are usually 2 to 5 inches wide, but they can be as large as 10 to 12 inches across. Each leaf is pointed at the tip. A slender petiole supports each leaf. The flowers are solitary or in small clusters, and they are found on short stalks in the upper leaf axils. Each yellow to yellow-orange flower is about 3⁄4 inch wide, with 5 sepals, 5 petals and many stamens which fuse to form a tube. The cup shaped seed pod is 1 inch in diameter, and it is composed of 5 to 15 hairy beaked carpels arranged in a disc. The carpels split at maturity, and each carpel contains 2 to 9 seeds. The hairy, dull seeds are gray-brown, rough and flattened and strongly notched. Each seed is about 1/8 inch in diameter. Velvetleaf grows from a strongly developed, slender white taproot with many smaller root branches.

• Mechanical: Small populations, and young plants are easy to control by hand pulling, before flower production. Velvetleaf germinates and grows later in the summer, after the last cultivation of row crops. Cultivation in row crops is effective if controlled late in the season, before seed pod production. Remaining plants should be hand pulled and removed or burned, since the seeds will ripen after the plant is pulled. Close mowing is effective if mowed prior to seed production. Seed bank tillage is also mentioned as a control method (Roeth et al. 1983).
• Biological: Quite a few organisms have been studied for use as biocontrol agents in the control of velvetleaf. The scentless plant bug (Niesthrea louisianica) reduced seed production by 98% (Patterson et al. 1987 as cited in Warwick and Black 1988). Velvetleaf is an early season host for tobacco budworm (Heliothis virescens) and bollworm (H. zea), which feed on the terminal shoots, young leaves and immature fruits (Stadelbacher 1981 as cited in Warwick and Black 1988). Fusarium lateritium and Colletotrichum coccodes are mycoherbicides studied for velvetleaf suppression. Several root nematdes (Heterodera marioni, Medoidogyne ssp.) parasitized velvetleaf under greenhouse conditions (as cited in Warwick and Black 1988).
• Herbicide: The rates for various chemical control options are found in the annually updated Pacific Northwest Weed Control Handbook. However, data is lacking in the Pacific Northwest. Refer to the State Noxious Weed Control Board site

For More Information:
Detailed information about Velvetleaf is available at the Washington State Noxious Weed Control Board Web Site.