Henbit: Give it a Break
by Jeffery Goss of Hurley, MO
Few winter annual weeds are more common than henbit. The term generally can refer to the lobed round-leaved Lamium amplexicaule, or to the square-stemmed Lamium perpureum, known in the Northwest as “purple deadnettle,” the “dead” being a reference to the plant’s lack of sting. But the name is ill-fitting since not only is it not a true nettle (Urtica), it is often vibrantly alive in the winters of inland North America, at a time when everything else looks dead!
For the most part, up until the past few years, humans and henbit have peacefully coexisted. But in the past decade, farm handbooks and herbicide ads have come out portraying henbit as an enemy, a threat to productivity on the farm. Because of its sheer commonness, do chemical salesmen see in Lamium a potential cash cow?
Due to its fuzzy leaves, henbit is not easily penetrated by herbicides. Rather than simply applying glyphosate, farmers must use a more broad-spectrum-toxic regimen of glyphosate along with some other agent such as Dicamba (2, 4-D). And for what purpose, we might ask! There are two main arguments to the present war on henbit. First, it competes with Bermuda and other pasture grasses in the southern U. S. This is somewhat true, but it only does so in the winter when the warm-season grasses are dormant. Livestock will graze the henbit, getting nutrition they would not receive from Bermudagrass alone. Moreover, the henbit dies off in early summer and the grass comes into its own. It is safe to say that no field of Bermuda has ever been wiped out by the presence of henbit. If that were so then many Southern gardeners, to whom Bermuda is an invasive nuisance, would be rid of it by letting henbit take over for awhile!
The other argument made against Lamium is that it allegedly decreases wheat yields and rye yields. According to a University of Missouri study, conducted near the Kansas border, henbit reduced wheat yields by 13 percent. But there are two facts often overlooked. For one, the winter wheat yield was lower only in portions of the field where henbit density reached 80 plants per square meter. (This study furthermore defined henbit as solely L. amplexicaule, and did not even count L. Purpureum which was almost certainly present also.) At densities of 18 plants per square meter, no effect on yield was to be seen at all. Besides that, the study was incidental rather than causal. The decreased yields may not have been the henbit’s “fault” at all.
True competitor plants, such as cheat grass and wild oats, often reduce the yield in winter wheat by half or more. Henbit is clearly not a competitor but a companion to small grains, as its unobtrusiveness at lower densities shows. But agronomically, high henbit densities are a hallmark of damp or low spots in the field. Due to lack of drainage, these are precisely the spots where wheat yields will likely be less, with or without the Lamium. In order to establish cause and effect, the scientists would have had to deliberately plant henbit in one area, diligently exclude it from another area of similar soil conditions, and sow wheat on both plots to compare the yield. They did nothing of the sort, but merely correlated areas of high henbit density to lower wheat yield. It might be easy for one to jump to a causal conclusion, but that would be a logical fallacy, in effect condemning an innocent plant to death for a crime it did not commit.
Moreover there is anecdotal evidence that a small to moderate amount of henbit can actually increase the yield of winter oats. By protecting the ground and holding in moisture in dry periods, and offering a barrier between the soil and the air’s temperature changes, henbit does a service to the winter oat, a moisture-loving and soil-temperature-sensitive crop.
If the current fad for the persecution of henbit continues, it will likely mean more herbicides entering the food supply for humans and livestock. Traditionally, even if not “organic,” small winter grains are free of pesticide and herbicide residues because they are not directly sprayed. Yet there are some who, it seems, would change that, by calling the henbit a villain to be done away with.
Not only is this misguided because of the reasons above, but also because it is an asset to the farm. Henbit’s purple expanses, which bloom in early spring and can be seen for miles in some places, are a major source of early pollen and nectar for honeybees. Even a small amount, growing at the woods’ edge or near the hives, will often be the first plants visited by hungry honeybees in late winter.
Henbit also checks erosion, because it forms a natural ground cover in shady places where not much else will be found to grow. Its seeds feed numerous species of birds, from juncos to doves, and even small mammals such as jackrabbits and chipmunks. It is enjoyed by domestic chickens, hence its name. Originally native to eastern Europe, it has spread over the past two millennia to most of the world’s cool climate areas, sometimes by wandering birds, sometimes by humans. Yet in most places it has naturalized well into the environment; botanists have never counted it as an invasive. The young leaves and stems, in winter, are edible and have been prepared in many ways, from soups to salads, boiled and served with butter or tomato sauce, or creamed. Even in lawns, though suburbanites find it an annoyance, its little whorls of flowers attract butterflies and other small creatures. It should be appreciated as a harmless and indeed beneficial species, far more harmless than the sprays now being promoted to control it.