Tuesday, March 26, 2024

Spring Weeds: Deadnettle and Henbit. What's the difference?

Its spring and spring plants are beginning to flower.  Have you ever notice the little purple/pink flowering plants that appear in your gardener on your walks? They are probably two of the most common spring weeds found in gardens: deadnettle or henbit.  How can you tell them apart?

Deadnettle or purple deadnettle and henbit are often mistaken for each other.  Once you know what to look for they are easy to differentiate.  First some background.  In some of the literature you will see these plants referred to as purple deadnettle(Lamium purpureum) and henbit deadnettle (Lamium amplexicaule).  Unlike some other nettles, these deadnettles do not sting.  In other words it is a "dead" nettle.  The common name henbit comes from observations that chickens like to eat it.

Deadnettle and henbit are winter annuals.  Both plants germinate in the fall and resume growth in the spring as the temperature rises, they set seed and then die in the late spring or early summer.

Square (quadrangular) stems

Purple deadnettle and henbit are members of the Laminaceae (also Labiatae) mint family.  There are over 250 genera of mints and approximately 7000 species.  Mints range in size from small herbaceous plants like henbit and purple deadnettle to trees.  There are certain characteristics that are common to all mints:
  • Square stems
  • Opposite, fragrant leaves
  • Bilabiate flowers 
  • Flowers ovary is segmented in four lobes
Purple deadnettle (on the left) and henbit (on the right) have square stems which are a common identification characteristic of members of the mint family.

Henbit - Photo by Dr. John Meade, weed scientist emeritus
Rutgers NJAES Cooperative Extension

Henbit (Lamium amplexicaule)
Lamium amplexicaule L. - henbit deadnettle - Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 3: 121. Provided by Kentucky Native Plant Society. Scanned By Omnitek Inc.- USDA Image Library





















Henbit has petioles on the lower leaves but not the upper leaves.  The upper leaves are clasping, hence 
the species name amplexicaule which means clasping.


Deadnettle - Photo by Dr. John Meade, weed scientist emeritus
Rutgers NJAES Cooperative Extension

Deadnettle (Lamium purpureum)
Lamium purpurem L. - purple deadnettle - Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 3: 121. Provided by Kentucky Native Plant Society. Scanned By Omnitek Inc. - USDA Imahe Library

The leaves on deadnettle all have petioles.  The length of the petioles tend to get smaller as you move upward on the plant.  The upper leaves on henbit do have petioles and leaves on the lower portion of the plant have long petioles.



Deadnettle (on the right)  and Henbit (on the left) Leaves

Notice that the leaves on the deadnettle are more triangular in shape and not as deeply lobed as the leaves on the henbit.  The leaves of henbit have a more rounded shape, are deeply veined and have hairs on the upper and lower surfaces.

Visit the weed control links listed below for information on controlling these weeds around the home or in the lawn.

NOTE: Always read and follow herbicide directions carefully. Do not use herbicides for controlling broadleaf weeds in turf such as dandelion in or near ornamental planting beds. If weeds are a persistent problem in landscape planting beds homeowners may wish to consult with a professional landscape contractor. 

Additional Information

New Jersey Weed Gallery - Rutgers NJAES Cooperative Extension

Weed Control in Home Lawns - Rutgers NJAES Cooperative Extension

Weed Control around the Home Grounds - Rutgers Cooperative Extension