While not technically an invasive species, black nightshade — also known as American nightshade, deadly nightshade, common nightshade or garden nightshade — is definitely a noxious weed. The glycoalkaloid compounds of Solanum ptychanthum, common to many nightshade species, are toxic to humans and livestock. When mature, black nightshade plants can stick to cutters, tractors, ATVs and other equipment, hampering access to ROWs and increasing the likelihood of accidental contact. Black nightshade may also harbor pests and diseases that can affect certain fruit and vegetable crops.
What Does Black Nightshade Look Like?
Black nightshade is just one of many different but closely related nightshade species; as such, accurate identification can present a challenge.
Seedling leaves are egg- or lance-shaped and are covered with small hairs. True leaves display a spade shape with smooth edges; the lower leaf surface may be purple. Later leaves feature a more pronounced egg shape, are darker green, and are covered in glandular and nonglandular hairs. Leaves may display smooth or slightly wavy edges; individual plants may have leaves with a slight scalloped or “sawtooth” edge.
During flowering, clusters of four to eight white star-shaped flowers can appear. At fruiting, small, pale green berries appear; berries will turn glossy and black. Black nightshade is a prolific seed-maker, producing 50 to 100 seeds per berry.
Black nightshade can be distinguished from other common nightshade species by the color of the flowers (silverleaf nightshade displays colorful flowers, while black nightshade flowers are white) or the color of the berries (mature hairy nightshade berries are green, yellow or brown, never black).
Mature black nightshade plants can vary in shape and color, though uncontrolled plants typically grow into 3- to 4-foot upright shrubs.
How to Control Black Nightshade Effectively
Though black nightshade can be found throughout the United States, it is most common to the Southern, Midwestern and Western regions. As with many undesirable plants, healthy beneficial plant populations can help reduce the severity of infestation.
An Integrated Vegetation Management strategy featuring selective herbicide applications is the most effective and practical method for control of black nightshade and will help reduce the risk of human or livestock exposure while also improving ROW accessibility.
Preemergence application is the preferred method of chemical control for black nightshade. Piper® EZ herbicide, applied at 20 fluid ounces per acre, offers residual control of this noxious weed and more than 75 other broadleaf and grass species. Cleantraxx® herbicide, applied at 3 to 4.5 pints per acre, can provide up to six months of residual control of black nightshade. With two modes of action, Cleantraxx herbicide offers enhanced weed control and resistance management.
Find more information regarding best practices for vegetation management in utility ROWs and adjacent lands at Utility.VegetationMgmt.com.
™ ® Trademarks of Corteva Agriscience and its affiliated companies. Cleantraxx® and Piper® EZ are not registered for sale or use in all states. Piper® is a registered trademark of Valent U.S.A. LLC. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. © 2023 Corteva.