Dallisgrass is a grassy weed (Paspalum dilitatum) that originated in Argentina and Uruguay. Back in the 1800s, it was first introduced in the U.S. as a forage plant that was not only fast-growing but also capable of surviving the southern climes. The name “dallisgrass weed” is commonly known as a tribute to a man named A.T. Dallis. He was a passionate supporter of importing the plants. Unfortunately, it was a major mistake that resulted in his name being forever synonymous with the pernicious weed. As luck would have it, both the dallisgrass weed and its two kissing cousins, thin paspalum and field paspalum, enjoyed their new-found home just a little too much and, before long, they grew completely out of control. All over the majority of the American south, Dallisgrass has effortlessly become naturalized, however, unlike its cousins, it’s also susceptible to a fungus that’s toxic to livestock.
The effective control of dallisgrass became a serious concern for both public and private lawn areas back then and continues to this day. It’s a perennial that’s quite coarse-textured, growing in ever-expanding circular clumps. In fact, it sometimes grows so large that its center will die out at the same time that its outer rings are continuing to smother lawns. This pesky weed’s short rhizomes make it capable of rooting easily in soil that is nice and moist, which makes it incredibly hard to control. It also thrives even in clay or sandy soil, loves nitrogen fertilizer, and can grow twice as fast as any turf grass. This creates serious obstructions and hazards for golfers and field athletes. It also forms unsightly tufts in lawns, creating a need for some serious weed control for homeowners.
There is a three-part solution to killing dallisgrass and it includes lawn health, pre-emergent treatment, and a post-emergent attack. Dallisgrass weed control requires maintaining densely planted turf that is exceptionally healthy via proper watering, meticulous mowing, and good fertilization. Quickly filling bare spots with sod or seed can help with preventing those invasive dallisgrass weed seeds when they try to take hold. The one surefire dallisgrass weed killer is a well-maintained lawn that is really thick, giving those unwanted seeds little to no room for germinating.
The second part of killing dallisgrass is the use of a pre-emergent weed control product. Since this weed is capable of producing copious amounts of seeds atop long spikes growing several feet tall, the seeds can be spread far and wide by animals, the wind, or just by lawnmower blades. A toxic pre-emergent herbicide that kills common crabgrass can also be quite effective at killing the dallisgrass but have to be watered into the soil for being completely successful.
Part three is post-emergent treatments for controlling dallisgrass for proper lawn care. The most environmentally-friendly (albeit labor-intensive) way is to dig out all offending plants. Since it is so labor-intensive, having a lawn service handle it could be advisable. In addition, spot treatments of a non-selective herbicide can help with minor infestations, however, care must be taken because non-selective herbicides will kill most plants it comes into contact with. Turf will die along with the dallisgrass weed, so quickly filling in those bare spots is a must.
Dallisgrass is often referred to as “a plague on lawns” all over the southern United States, however, some basic knowledge and diligence can result in this pernicious weed being completely eradicated from any lawn.