The issue: Many invasive weeds started out as ornamental plants that escaped cultivation. Weed issues are cheaper to solve before they become a serious problem. Be proactive to keep potential plants from reaching the weedy stage.
Bittersweet nightshade (Solanum dulcamara) was introduced from Eurasia as an ornamental. This relative of tomatoes is a semi-woody, climbing, perennial vine that has become an invasive weed throughout North America. It thrives in rich, moist to wet soils, as well as full shade and full sun. The dark green leaves have a purple tinge. Smaller leaves are simple and larger leaves have two lobes at the base. The star-shaped, purple flowers have contrasting, yellow stamens that make them quite attractive. The small berries are bright red when ripe.
The plant spreads mostly by seeds and rhizomes (underground stems). The vines readily root as they creep along the ground. It is most often found growing up through shrub beds and along fence lines. All parts of the plant are toxic to humans and the red berries are attractive to children.
Integrated pest management options:
· Mechanical: Till or dig up the plant and remove the underground stems before seeds mature. Repeat whenever new sprouts appear. Proper lawn care will keep it out of grass.
· Cultural: None.
· Biological: None known.
· Chemical: Foliar applications of glyphosate may be effective, but it is usually growing up through desirable plants, so herbicide application can be difficult. Be sure the target weed and crop or landscape situations are listed on the product label. Always read and follow herbicide label directions.
Combine them:
Combine different IPM options over a period of years to help improve the effectiveness of your efforts.
For more information, contact Ron Patterson, University of Idaho Extension horticulture/agriculture educator in Bonneville County.
