What is it?
Nutsedge, also known as nutgrass, is a weed commonly found in lawns during the summer. These weeds stand taller than the grass in your lawn and are notoriously hard to get rid of given their immersive root systems. Nutsedge is a perennial sedge, meaning it is a grass-like plant that will live for at least two years and will come back year after year, This plant can be hard to control due to the inability of most weed killers to effectively reduce the population and their ability to withstand drought.
The key identifying feature for these difficult weeds is their triangular stems and distinct center rib that create a "V" shape. The bright yellow-green leaves of yellow nutsedge stand out clearly against turf, as do the dark green leaves of its purple relative. Left to grow tall, nutsedges produce distinctive spiky flower clusters: yellow-brown for yellow nutsedge and purple-brown for purple nutsedge.
How Does it Spread?
Nutsedge outbreaks often start in moist, poorly drained lawn areas, where they quickly develop into large colonies. Nutsedges spread and reproduce in several ways. Plants may flower and release seeds that germinate and sprout into new plants. These weeds also spread via underground stems, known as rhizomes, which send up shoots that become new plants. However, the most prolific means of nutsedge reproduction is through underground tubers known as "nutlets."
Yellow nutsedge rhizomes only produce single nutlets, but purple nutsedge rhizomes can produce rows of nutlet tubers. Both species of nutsedge plant can produce thousands of nutlets each year, which can each eventually produce nutsedge patches several feet wide.
Most nutlets form within 6 to 10 inches of the surface but can reach up to 18 inches deep. Due to their depth, nutlets are protected from most of the effects of herbicides and cold weather, which would help kill them. This allows nutlets to stay hidden in the soil for up to 10 years before eventually emerging to produce new nutsedge plants.
By practicing good lawn care basics, you can protect against nutsedge invasions and give your grass an advantage over these aggressive weed pests. Healthy, vigorous grass is an excellent defense against yellow and purple nutsedge in lawns.