Field horsetail, the little jointed plant sometimes described as a miniature Christmas tree, is causing concern to some producers. At many meetings this winter, questions have been asked about why this little weed seems to be on the increase and what can be done to control it. The simple answer is that once we hit a stretch of dry years it will decrease and nothing really controls it.
Dr. Doug Derksen, AAFC in Brandon said the presence of the weed is an indication of the type of soil and more importantly, the subsoil. "Field horsetail is a native plant that tends to be found in ditches or fields where the soil is sandier and the subsoil moisture is high, within 2 - 3 feet of the surface. In years of high rainfall and under these soil conditions, it seems that field horsetail flourishes," he said.
Producers are often concerned when later in the growing season, they find an area of the field where there's no crop but lots of field horsetail. It appears that the horsetail has choked out the crop. Dr. Derksen said, "In fact, it just may not have been a good environment for the crop seedlings to become established. The horsetail is adaptable and begins to grow when there's no competition from the crop". Dr. Derksen added that more research on the weed and its competitive ability is required.
Field horsetail is not an easy weed to control. Dr. Derksen explained, "The plants tend to be rather small and spindly without any leaves so there's no leafy tissue to take up the herbicide. And the stems and branches have waxy cuticles that make it difficult for herbicides to penetrate".
There are a couple of herbicides registered for suppression of field horsetail, however, it may not be worth the hassle and the expense. Before heading in to the local retailer for product, evaluate the field. If the horsetail seems most prevalent on the lighter soil or is confined mainly to the low spots in the field, it might be better to turn a blind eye to the horsetail and spend your herbicide dollar on the weeds that have greater yield-robbing potential.