Every spring, questions pour in about the purple weed suddenly appearing in lawns and landscapes. The culprit is most likely one of two closely related plants: purple deadnettle (Lamium purpureum) or henbit (Lamium amplexicaule).
These two weeds are frequently confused — and for good reason. Both belong to the mint family, share square stems and an ascending growth habit, bear opposite leaves and purple-to-pink flowers, and behave as winter annuals. Look closely, though, and a few key traits set them apart.
Key ID traits for purple deadnettle:
- Upper stem leaves are triangular with pointed tips and a purple tinge
- Upper leaves have petioles (short stalks) and are not attached directly to the stem
Key ID traits for henbit:
Upper stem leaves are rounded with deep lobes and prominent venation
Upper leaves attach directly to the stem with no petioles
Leaves are densely pubescent (hairy)
As winter annuals, both species germinate in fall or early spring, flower, set seed, and then die back as temperatures rise. Preventing seed production is the cornerstone of long-term management. Tillage and herbicides are both effective options, though applications made now — while plants are in flower — are unlikely to provide complete control. For best results, treat in fall or early spring before flowering begins.
Ground Ivy
Also known as creeping Charlie, ground ivy (Glechoma hederacea) is another spring-blooming weed with purple flowers that often draws questions. Unlike the deadnettle and henbit, it is a perennial that forms dense, spreading patches in sun or shade alike. Its leaves are rounded with scalloped edges, prominent veining, and a rough upper surface. Small, funnel-shaped flowers appear in clusters at the leaf axils. Ground ivy resembles henbit in some respects but can be distinguished by its habit of rooting at stem nodes — something henbit does not do. Cultural practices such as improving surface drainage, aerating compacted soil, and watering deeply but infrequently can help discourage encroachment. Both pre- and postemergent herbicides are available for more direct control.
Wisteria: Beautiful but Beware
Each April brings a familiar and bittersweet sight: the cascading purple blooms of Chinese wisteria (Wisteria sinensis) and Japanese wisteria (Wisteria floribunda). These deciduous, woody perennial vines are widely planted for their prolific, fragrant flower clusters — which can range from 6 to 20 inches long — but they come with a serious downside. Once established outside cultivation, they spread aggressively into woodlands, displacing and choking out native vegetation.
The two species can be told apart by their twining direction: Chinese wisteria winds counter-clockwise, while Japanese wisteria winds clockwise. Both produce 4–6-inch velvety seed pods and spread readily from seed, as well as by rooting wherever stems contact the ground.
A better choice for most landscapes is our native American wisteria, Wisteria frutescens, found naturally in moist bottomland forests throughout the southeastern United States. It is far less aggressive, produces shorter flower clusters, blooms in summer rather than spring, and bears smooth (not fuzzy) seed pods. When selecting any vine or ornamental for your garden, take time to research its growth habits and invasive potential — it can save a great deal of trouble down the road.
