Horsenettle Solanum carolinense
IDENTIFICATION – If you try to pull this perennial, you’ll quickly discover its prickly stems and leaves. Horsenettle often grows in colonies because it spreads by underground rhizomes. Older plants can grow to be 4 ft. tall on tough, woody stems.The star-shaped flowers are white or light-blue with five petals. Later, juicy, orange berries form, then eventually dry to look like small, wrinkled nuts.
FAVORITE CONDITIONS – This weed grows in almost any soil and is tolerant of sun or part shade. Since it’s a perennial, you won’t usually find it as a mature plant in frequently cultivated areas, such as vegetable gardens. But it thrives and spreads in places where you don’t disturb its root system, for example in shrub borders or perennial beds. Remove horsenettle plants near vegetable gardens. It often attracts insects, such as flea beetles, that also chew on the leaves of tomatoes, potatoes and eggplant. That’s why horsenettle foliage is often riddled with tiny holes. In addition, several destructive viruses that affect vegetable crops overwinter in horsenettle roots and infect new crops each year.
CONTROL – You can dig out this prickly weed. But if you break off or miss any part of the root, horsenettle will be back. Dig it up while the plant is young before it sets seed and before the roots have spread. It’ll take you several years of diligent digging to eradicate it from your garden. Glyphosate herbicides will also kill horsenettle if you spray in late spring or summer while the weed is actively growing.