Weeds Galore We have been blessed with some wonderful rainfall this spring. The rainfall provided some good early grazing from some of our cool-season grasses like Texas Wintergrass, ryegrass, and others. It has also really got our warm-season perennial grasses off to a good start. Unfortunately, it has provided a good start for many varieties of weeds. This is starting out to be one of the best years for weeds that we have had in a while. Here are a few of the weeds that I see really exploding across the county.
In last week’s article, I talked about ragweed, but I am amazed at how much I am seeing and how fast it is growing. Ragweed is a perennial and can produce new growth from roots. This year’s seedlings will not produce seed until next year. Ragweed is an early germinator; this early germination allows it to get a jump on grasses and decreases the chance for the grass to shade out the ragweed. All ragweed can be controlled effectively with herbicides, but timing is very important. There is a myriad of herbicides that work well on ragweed, here are a few: Milestone, GrazonNext, ForeFront, Cimmarron Max, Grazon P+D, Range Star, and 2,4-D amine applied at label rates. Control results can be excellent, exceeding 90% control for each herbicide. The kicker is the average size of the ragweed at the treatment site needs to be 6” or less.
Marshelder is another highly invasive, native, warm-season annual weed. It is commonly called sumpweed. While more prevalent in moist seepy areas, I have seen it in good fertile sandy Bermudagrass fields as well. I have recently seen a couple of good hay fields that are covered in marshelder. Be careful turning livestock out in fields with heavy infestations of marshelder as it is a toxic weed and is known to cause abortions in all livestock. Marshelder is relatively easy to control with the same herbicides used for ragweed, but again it must be sprayed early, best before the plant reaches 6” in height.
Silverleaf Nightshade is an upright prickly perennial plant with velvet like leaves. It is a very hardy, aggressive weed with a deep extensive root system from which the plant spreads. Silverleaf nightshade though not often consumed, is a toxic plant to cattle and horses. Usually, I only see cattle poisoned when they are locked in a trap with the plant and mostly due to boredom they may feed on the leaves or berries. Silverleaf Night Shade is harder to control and will require more specialized herbicides to control. It also needs to be sprayed in the spring while it is blooming for best control. Interestingly, I read where nightshade was used to treat rattlesnake bites by medicine men. They would chew the root and then suck the wound to remove the venom and then apply more chewed root to the swollen bite area. I have no idea if this works and I recommend if you get bit by a rattler, just go on to the hospital.
Marestail or Horseweed is another weed that seems to be just about everywhere now. I used to seed a lot of it in orchards and cropland, but it is now very common in pastures and hay meadows. Marestail is a winter/spring annual that emerges in the fall and early spring as a rosette. Marestail makes the headlines these days due to its resistance to herbicides, mainly glyphosate. It is a very prolific seeder and prefers well-drained disturbed soils, but like I said, I am seeing it show up much more in pastureland. Due to its herbicide (glyphosate) resistance, it has become a significant threat and if left untreated can cause as much as a 40% loss of yield, mostly in crops. It is best controlled while still in the rosette stage and most pasture broadleaf herbicides are still very effective at controlling it.
I know there are other weeds out there ready to steal nutrients and decrease your productivity, but right now these are the ones I see the most in pastures and meadows. Be sure you are inspecting your fields and making every effort to treat timely with the proper products.