Nutsedge is a common and pesky weed that can quickly take over lawns and gardens. Getting rid of nutsedge takes some effort, but it can be done through a combination of methods. Here is a comprehensive guide on how to identify nutsedge and tips for getting rid of it effectively.
What is Nutsedge?
Nutsedge (also known as nutgrass or Cyperus rotundus) is a perennial sedge weed that spreads through tubers that form at the ends of rhizomes underground. There are two common types of nutsedge:
- Yellow nutsedge has a light green triangular stem and yellowish flowers and seeds.
- Purple nutsedge has a purple tinged stem and darker purple or brown flowers and seeds.
Both types produce nutlets or tubers that allow them to spread aggressively. Nutsedge is most common in warm climates and thrives in moist, organically rich soils.
How to Identify Nutsedge
There are a few key features that can help identify nutsedge:
- Triangular stems – The solid, wiry stems have a triangular cross-section rather than round. This is a key way to distinguish nutsedge from grass.
- No auricles – Grasses have clasping auricles where the leaf blade attaches to stem. Nutsedge stems do not have auricles.
- Tubers – If you dig near the base of the plant, you will find tubers (small nutlike structures) that allow it to reproduce.
- Leaf arrangement – The long, grass-like leaves are arranged in ranks of three along the stem.
- Seed heads – Yellow nutsedge produces a yellowish branched seed head. Purple nutsedge will produce a deeper brown/purple seed head.
If you spot weeds with these features, chances are you are dealing with nutsedge. Confirm by digging to check for tubers.
Why Get Rid of Nutsedge
Getting rid of nutsedge is important for several reasons:
- It spreads aggressively through tubers underground, allowing it to takeover gardens and lawns quickly.
- It is difficult to control and can choke out desirable plants.
- The wiry stems and leaves are difficult to cut or mow.
- It produces a lot of pollen which can aggravate allergies.
- It looks unsightly and can take away from the appearance of a nicely manicured lawn.
How to Get Rid of Nutsedge
Getting rid of established nutsedge takes effort and consistency. Here are some effective methods:
Hand Removal
Manually digging up nutsedge can work for small infestations. Use a nutsedge hook, hori hori knife, or trowel to dig under the plant and remove the tubers. Removing tubers is key to prevent regrowth. Discard the plant and tubers in trash, not compost. Repeated weeding will be needed to deplete the tuber bank.
Smothering
Smothering nutsedge with mulch, tarps, or landscape fabric can be effective. Cover the plants thickly to block light. Leave covered for a full growing season. The lack of light and air will kill nutsedge over time.
Tillage
Frequent shallow cultivation with a hoe or tiller can control nutsedge by bringing tubers to the surface where they dessicate and die. Till every 2-3 weeks and remove dead foliage. Don’t bury tubers deeper as this helps them spread.
Flooding
Flooding an area with 3-6 inches of water for 4-6 weeks during growing season will create an anaerobic environment that kills nutsedge tubers. Drain and till area after flooding period.
Herbicides
There are several effective nutsedge herbicides:
- Sulfentrazone (ex. Dismiss) is selective for sedges and safe on most turfgrasses. Can also be applied to garden beds when plants are protected from spray.
- Halosulfuron (ex. Sedgehammer) provides post-emergent control for yellow and purple nutsedge.
- Imazapyr (ex. Arsenal) provides non-selective, total vegetation control of nutsedge for spot treatment. Use caution around desired plants.
When using herbicides, always read and follow label directions carefully. Repeated applications are likely needed. Combining herbicides with other methods provides the best control.
Lawn Improvement
Improving your lawn’s health through aeration, fertilization, irrigation and overseeding can help reduce nutsedge infestations long-term. A thick, healthy lawn is able to better outcompete weeds.
Prevention Tips
To avoid major nutsedge problems in future seasons:
- Watch for new infestations and immediately dig up small patches when spotted.
- Avoid overwatering lawns and gardens. Allow soil to partially dry out between waterings.
- Use drip irrigation where possible to avoid moistening whole areas.
- Improve drainage in poorly draining areas.
- Do not allow nutsedge plants to go to seed and spread tubers further.
- Clean tools, shoes and tires after working in infested areas to avoid spreading tubers.
- Use mulch to block light from reaching the soil surface.
- Apply corn gluten meal in early spring to inhibit seed germination.
With persistence using cultural, mechanical and chemical control methods, nutsedge can be successfully eliminated from lawns and gardens. Consistency is key – it often takes multiple seasons to fully deplete the nutsedge tuber bank. But stopping nutsedge’s spread will make your landscape more beautiful and healthy.
Frequently Asked Questions
What is the best herbicide for killing nutsedge?
Some effective nutsedge-specific herbicide options include sulfentrazone (Dismiss), halosulfuron (Sedgehammer) and imazapyr (Arsenal). Always read labels to confirm the product is effective on nutsedge and follow directions carefully.
Does vinegar kill nutsedge?
Vinegar can provide some control on young nutsedge plants, but it does not kill the tubers so nutsedge will regrow. More effective options are recommended.
Will Roundup kill nutsedge?
Standard glyphosate formulations like Roundup may injure above-ground growth but do not provide effective control. Glyphosate products specifically labeled for nutsedge (often containing sulfentrazone) can provide better control.
Does borax kill nutsedge?
Borax does not effectively control or kill nutsedge. The tubers deep underground are not affected by borax sprinkled on the soil surface.
Will mulch get rid of nutsedge?
Mulch alone will not get rid of established nutsedge but can help prevent new growth by blocking light from reaching the soil surface. Combine with hand weeding or herbicides for best control.
Can I just keep mowing nutsedge?
Frequent mowing will prevent nutsedge from going to seed but does not kill the plant or control the spread of tubers. Combine mowing with other methods like tillage or herbicides for more effective control.
Conclusion
Nutsedge is a challenging weed, but with persistence it can be eliminated. The key is depleting the underground tubers to stop its spread. Combining manual removal, cultural practices, and targeted herbicide applications provides the best chance of success over time. Pay close attention to preventing new infestations. With a comprehensive approach, you can get rid of nutsedge and reclaim your lawn and garden space.