Nutsedge – Possibly The World’s Worst Weed

Sorry…no pretty pictures to inspire you in the landscape this week. 

It’s time to discuss what is often the most challenging part of lawn care this time of year….Nutsedge Control!

And I know, I know, I have called many weeds “the world’s worst weed”, but If I am asked what are some of the weeds that give all lawn enthusiast the most difficulty, there is a 100% chance I am going to respond without hesitation: “NUTSEDGE!” 

Nutsedge is fast growing, has an upright growth habit and light green in color. Because it grows nearly twice as fast as your turf and is lighter, it ruins the best maintained lawns within a couple days of mowing.   

What does nutsedge look like?

Commonly called nutgrass because it looks like a grass, but it is a sedge with triangular ‘V’ shaped leaf blade arranged in groups of three at the base.

Nutsedge grows faster, has a more upright growth habit, is lighter in color and has a thicker, stiffer leaf blade than your turf grass.     

What are the best growing conditions for nutsedge?

Nutsedge thrives in moist, tight soils.  It is common to find it growing in areas of poor drainage, around irrigation leaks, and in lawns that are watered too frequently. 

Although nutgrass starts in overwatered lawns or areas of poor drainage, once it is established it thrives with normal irrigation, in dry lawns and even through a drought leading many to believe nutgrass has more to do with the soil structure than moisture. 

Nutsedge also prefers full sun and doesn’t grow well in shade and typically isn’t a problem in shady lawn areas.

Nutsedge first emerges in May and continues to thrive until the first frost.

Why is nutsedge so difficult to control?

Nutsedge is a perennial weed. Perennial weeds are always more difficult to control.  But nutsedge is one of the toughest, because it spreads by underground tubers.  Four to six weeks after the first blades emerge, typically in late June to early July, nutsedge begin forming new tubers (nutlets) and rhizomes (underground stems). 

The tubers grow 6-12” deep and are referred to as nuts - thus the common name of nutgrass.  Nutsedge spreads by growing rhizomes which produces more nuts.  Weeds that propagate through tubers and rhizomes are very difficult to control because unless you get control of the rhizome and tuber, the plant will sprout new growth within a few days.  Also, tubers can remain dormant in soil for three seasons.

Be proactive.  With the first sign of nutsedge, take action. Nutsedge is much harder to control once it has been allowed to spread and mature. 

Weed killers labeled for use on nutsedge will be either a contact killer or a systemic.  A contact herbicide will kill only the leaves and the tubers and rhizomes will remain active if you make only a single application. Systemic products will translocate through the plant to the tubers and rhizomes. 

Remember, single applications of most herbicides labeled for nutsedge will kill the plant leaves but leave the nut unaffected.

Because it is not a grassy or broadleaf weed, common herbicides will have little to no control.  For nutsedge control you must search out products specifically labeled for nutsedge.

In late June to early July, uncontrolled areas of nutsedge will begin to multiply and take over areas.

A few herbicides available at most garden centers labeled for nutgrass include:

• Basagran – A second application must be made 7-10 days after the first application.

• Image Nutsedge Killer – Requires a second application 3-4 weeks later.

• Sedge Hammer Plus – Must have a surfactant mixed with the herbicide to be effective and a second application will need to be made in 6 weeks.

• Ortho Nutsedge Killer and Gordon’s Trimec Nutsedge Plus – Both require follow up treatments every 4 weeks.

Please read the label and follow it.  You will need to know your turf type.  Read the label to make sure you can use the product on your lawn.

Is pulling nutsedge a good idea?

Pulling nutsedge is only recommended when the plant is very small before nuts start to develop on the rhizomes (May through June).  Once nuts start to develop, you must remove the nut when pulling the weed, which is typically 6-12” below the surface. 

If you pull the weed and leave the nut behind, new plants will emerge very quickly.   If pulling, the best method is to dig at least 12” deep and 12” wide to get all the tubers.

Research suggests that anytime the tuber is stressed, by either pulling the top off or by killing the top without killing the tuber itself (the result of a single application of an herbicide), the tuber multiples.  Therefore, many people experience more nutsedge after they have pulled or sprayed.

Cultivating nutgrass, such as in landscape beds, is ineffective.  All you are doing is redistributing the tubers and rhizomes.

What else can I do to be proactive in preventing nutsedge?

• Aeration is a great way to reduce the chances of nutsedge starting and spreading.  Aeration reduces soil compaction and reduces the best growing conditions for nutsedge. 

Our experience is lawns which are aerated annually rarely have significant nutsedge problems.

• Water only based on need and infrequently.  Overwatering, keeping your lawn too wet, promotes the best growing conditions for nutsedge. Water deep.  Allow the soil surface to become dry between waterings.

• Correct water leaks in your sprinkler system promptly.  Nutsedge will stake a claim to any areas that become waterlogged.  

• Along the same line of thinking, correct poor drainage areas.  Often patches of nutsedge are an indicator of poor drainage. 

If you find yourself struggling with nutsedge, give Hall | Stewart a call, (405) 367-3873. 

Hall|Stewart’s 7-Step Lawn Care Program includes nutsedge control.  One of the benefits of subscribing to our full program is we do not charge extra for nutsedge control.  And, because we know the presence of nutsedge can quickly tarnish a great looking lawn, we use the most advanced nutsedge control herbicides available to the industry.

Nutsedge is one of the more aggressive and persistent weeds you will encounter.  Control of nutsedge can be a long process.  It is a marathon, not a sprint.

Success involves both the best cultural practices (aerating, watering, and mowing) and timely use of quality herbicides labeled for the control of nutsedge.

Lorne Hall

Hall | Stewart Lawn + Landscape

(405)367-3873

Why is a Spring Pre-Emergent So Important?

There are many reasons for weeds.  Weeds can be the result of poor growing conditions due to lack of moisture, weeds are typically worse when soil is compacted, and weeds are always more prevalent in thin turf.   

But, there is one very important thing that will make the biggest difference in the amount of weeds you have this year – the early spring pre-emergent lawn care application.

Hall | Stewart Lawn + Landscape has been actively applying the early Spring Pre-Emergent for the past few weeks.  Our goal is to make sure all of our clients have taken the necessary step to prevent weeds this year.

We get involved in a lot of conversations about weeds and wanted to share with you a few of the most common questions.

Why is the early spring pre-emergent so critical? 

Summer annual weeds come up every year.  They germinate, grow, reseed, and die all in one year.  They can be booth grassy weeds and broadleaf weeds.  A quality pre-emergent herbicide will prevent many types of weeds.  But, the most aggressive annual grassy weed is crabgrass.  If you had a single crabgrass plant in your lawn last year, or your neighbor’s lawn had crabgrass, or your neighbor’s neighbors had crabgrass, there is a real strong chance you will have crabgrass this summer if you do not apply a pre-emergent to your lawn this spring. 

Why am I so sure you will have crabgrass if you skip the early spring pre-emergent application?

A single crabgrass plant produces thousands of seeds.  Because crabgrass is so prolific, even the nicest lawn in your neighborhood last summer can be full of crabgrass this summer if a pre-emergent is not applied this year.    

Mid summer lawn that did not have any pre-emergent in the spring.

Because crabgrass is fast growing and spreads quickly, it can have a dominant presence in your lawn by May without a spring pre-emergent.

What is the best timing of the first lawn care application?

With thousands of seeds laying dormant in the soil, as soon as conditions are right, germination will begin.  Germination of crabgrass occurs typically in mid March in central Oklahoma.  The key determination is soil temperature.  When soil temperatures consistently reach 55 degrees germination occurs.  This week, soil temperatures in the Oklahoma City area are in the mid-40s.  For the best prevention of summer annual weeds, your first lawn care treatment needs to be applied by the end of February.

Will one pre-emergent application per year be enough?

Crabgrass is one of the first annual weeds to germination each spring, but it does not germinate all at once.  Germination of seed will continue throughout the summer.  Other summer annual grassy weeds such as, goosegrass, foxtail, and sandbur will germinate soon after crabgrass.  Knotweed and spurge are summer annual broadleaf weeds that will germinate even later.  Summer annuals germinate from mid-March through early summer.  Most pre-emergent herbicides will not provide coverage the entire summer growing season.  The herbicide creates a blanket over the soil to prevent seeds from germinating. Rain, irrigation, foot traffic, all combine to break down the herbicide.  Therefore, full summer control is only obtainable if you repeat the application again in late spring: April-May, approximately 6-12 weeks after the first application.

Does a pre-emergent need to be applied as a liquid or can it be spread as a granular?

Pre-emergent herbicides come in both forms and for the best results the product needs to be applied evenly to the lawn to create a weed barrier.  With either product, watering the product into the root zone is important.  Always follow directions.  When doing it yourself never over apply a pre-emergent as it can stunt root growth. 

Why are pre-emergent sprays green?

Actually they are not.  Some lawn care companies add dye to their herbicide to use as a marking pattern.  We are not a proponent of using a dye.  Most pre-emergent herbicides have a light coloring that aid the lawn care professional in applying the product evenly to the surface.  We find dyes messy, they give the natural landscape an artificial look, and add an unnecessary chemical to your landscape.

Most importantly, if you have not applied a pre-emergent to your lawn yet this year, please do not delay. 

If you need assistance in making sure your lawn is weed free and healthy this season, please call Hall|Stewart Lawn + Landscape at (405)367-3873.

Lorne Hall