HPIPM:Henbit

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Asteranae
Order	Lamiales
Family	Lamiaceae
Genus	Lamium

Scientific Name

Lamium amplexicaule

Common Name

henbit

Henbit (Lamium amplexicaule)

Compiled by Mark B. Major, Montana State University, Teton County Extension

and Marjolein Schat, Montana State University from the following sources:

http://plants.usda.gov/factsheet/pdf/fs_laam.pdf

Identification and Life Cycle

Henbit (Lamium amplexicaule) is a cool season annual weed in the mint family (Lamiaceae). Henbit has square stems that reach 6 to 15 inches in height. Leaves those on the stem that are not associated with flowers have petioles. Upper leaves have no petioles and occur just below flower clusters. Both types of leaves are somewhat rounded, coarsely toothed, and occur in pairs on opposite sides of the stem. Flowers are about 1 1/2 inches long, purple, and have hairy bracts. Unlike many plants in the mint family, henbit does not have a strong or distinctive odor. Seeds are found in nutlike fruits (mericarps) and are light to dark brown. Henbit has a fibrous root system.

Habitats

Henbit thrives in cool, moist areas and occurs in yards, parks, roadsides, fallow fields, winter grain crops, pastures, and turf grass.

Impacts

Henbit can be highly competitive in newly seeded areas. Henbit has been found to be an overwintering host for soybean cyst nematode. Henbit is also an alternative host for corn earworm.

Biology and Ecology

Henbit reproduces by seeds. Seeds germinate in late summer or fall and the plant is dormant over the winter. Henbit flowers in spring or early summer and then dies. Henbit can produce over 2000 seeds per plant under ideal growing conditions.

Management Approaches

As an annual that reproduces by seed, management techniques that prevent seed production are most effective. Henbit can be controlled by both mechanical and chemical controls.

Biological Control

There are no biological control agents available for henbit.

Mechanical and Cultural Control

Henbit thrives in cool, moist places and growing conditions may be made less favorable by lightening soil or improving drainage. Small infestations can be controlled by hand pulling.

Chemical Control

A variety of chemical control options are available for control of henbit. For herbicide recommendations for specific grain rotations and weeds in Montana, please see the MSU Herbicide Chooser Tool.

Examples of herbicides that can be used to manage henbit

Consult herbicide labels for additional rate, application, and safety information. Additional herbicide information can be found at http://www.greenbook.net.

Herbicide Active Ingredient trade name	Mode of Action	Product per Acre	Application Time or Growth Stage
Rangeland, Pasture, and Non-cropland
Triclopyr; clopyralid	Action like indole acetic acid (synthetic auxins)
*Redeem R&P		1.5 - 2 pints	Apply when weeds are actively growing.
2,4-D; glyphosate	Action like indole acetic acid (synthetic auxins)
*Campaign		1.5 - 4 pints	Apply before henbit reaches seedhead formation. -	Alfalfa
Pendimethalin	Microtubule assembly inhibition
*Prowl H20		4 pints	Apply to established seed alfalfa before alfalfa exceeds 12 inches in height, but prior to emergence of weeds.
Imazamox	Inhibition of acetolacetate synthase ALS (acetohydroxyacid synthase AHAS)
*Raptor		5 - 6 ounces	Apply Raptor® herbicide as an early postemergence treatment when weeds are actively growing and before they exceed a height of 3 inches.
Peas and Lentils
Glyphosate	Inhibition of EPSP synthase
*Roundup Original		26 ounces	This product may be applied as an over-the-top broadcast spray oras a spot treatment to control labeled weeds in dry beans, peas, lentils or chickpeas. Apply when henbit is 6-12 inches tall.
Grass Grown for Seed
Dicamba	Action like indole acetic acid (synthetic auxins)
*Clarity		8 - 24 ounces	Apply to small actively growing weeds at a rate of 8-16 ounces to seedling grasses when grass crop is at the 3-5 leaf stage. Up to 24 ounces may be used on established perennial grasses.
Wheat and Barley
Chlorsulfuron; metsulfuron	Inhibition of acetolacetate synthase ALS (acetohydroxyacid synthase AHAS); action like indole acetic acid (synthetic auxins)
*Finesse		0.2 - 0.3 ounces	Pre-plant/pre-emergence applications are recommended for winter and spring wheat only. Post-emergence (winter wheat and winter barley): Apply after crop reaches 2-leaf stage, but before boot stage. Post-emergence (spring wheat and spring barley): Apply after crop reaches 2-leaf stage, but before flag leaf is visible.

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

References

For more information and images please visit IPM Bugwood. http://www.ipmimages.org/search/action.cfm?q=henbit