Akin to Henbit
In late March and early April, many folks notice a purple flowering plant appearing in yards, gardens and fields. These are most likely purple deadnettle or henbit. These are winter annuals and part of the mint family that are present in normal years. Being winter annuals, they have a shallow root system and typically complete their life cycle before growing season. They may be more noticeable during winters with more moderate weather conditions.
According to WVU Extension Weed Specialist Dr. Rakesh Chandran, “mild winter seasons allow these weeds to get a head-start on the grass and other species.”
These flowering plants do provide an early feed source for our pollinators. Bees
that are getting active at this time of year are attracted to the flowers on these
plants for nourishment. It is important that we protect our pollinators as they
do important work in the field and garden.
There are several options to consider to address these “weeds” depending on the situation.
Purple Deadnettle Control
Purple Deadnettle Control for the Lawn
In lawns, the purple deadnettle and henbit can compete for space with desired grass species. Bare spots left behind may allow summer annuals, such as crabgrass, to take over. The options include hand-weeding or mowing small areas and chemical treatment for larger areas. One effective herbicide, called Q4, controls actively growing winter annuals in lawns.
Since most of these winter annuals germinate during the preceding fall, application of a pre-emergence herbicide in September and October could result in a lawn relatively weed-free during the following spring. Applying an effective herbicide during that time could help control other pesky summer weeds such as dandelions, white clovers, plantains and crabgrass the following year. Therefore, fall is the best time for homeowners to consider a treatment for these unwanted plants and the results will be noticed the following year.
Homeowners may consider reseeding any bare spots with desirable grass species. Again, fall (September) is a good time of the year to do so, followed by spring (April). A soil test is recommended and WVU Extension or West Virginia Department of Agriculture can assist with soil testing.
Purple Deadnettle Control for Small Home Gardens
In small home gardens, tillage will likely offer the best control measure. Tilling or cultivation will reduce the production of seeds, facilitate the warming up of soils and trigger germination of other weed seeds. After leaving such areas stale for a few weeks, a light secondary cultivation will control additional weeds after which the crop can be planted and mulched to prevent further weed competition. It may not be necessary to apply herbicide products in home garden settings due to plant sensitivity.
Purple Deadnettle Control for Fields
In fields that are cultivated or prepared for field crops, purple deadnettle and henbit are not generally a concern. Since most herbicide packages for field crops employed in either burndown or post emergent treatments should be sufficient to control these unwanted plants.
As always read the label and follow all directions for use of any products applied to lawns, gardens or fields for control of unwanted pests.
For more information on these plants or recommendations, contact your
local WVU Extension Office.
David Workman, WVU Extension Agent Emeritus – Agriculture and Natural Resources
Last Reviewed: June 2017
Recommendations for the use of agricultural chemicals are included as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services does not imply endorsement by West Virginia University Extension nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your county Cooperative Extension agent.