What is Nutsedge?
Nutsedge or nutgrass is technically not a grass, but it looks like one, only it grows faster than regular turf grass and sticks up like a bladed yellow weed. It can pop up both in garden beds and in the lawn. Nutsedge has a triangular stem and roots contain small bulbs or tubers that make fighting nutsedge very difficult.
How Nutsedge Spreads
Under optimum conditions, a network of nutsedge plants arising from one tuber can produce 100 or more tubers in about 100 days. About 80–95 percent of the tubers are located within the top 6 inches of soil. However, tubers have been reported to be present as deep as 18 inches. Once tubers form, they can remain viable in soils for at least two years if they retain moisture. They can survive even when soils are very dry for short periods. However, if tubers are brought to the soil surface for about one week under sunny conditions, they dry out and die.
Damage to Lawns
Nutsedges are a problem in lawns because they grow faster, have a more upright growth habit, and are a lighter green color than most grass species, resulting in a nonuniform turf. In gardens and landscapes, nutsedge will emerge through bark or rock mulches in shrub plantings and vegetable and flower beds throughout the growing season.
The best approach for avoiding nutsedge problems is to prevent establishment of the weed in the first place. Once established, nutsedge plants are difficult to control. New infestations of nutsedge occur when tubers are moved from one area to another on equipment or in soil, plant containers, or among roots of transplants so check containers and equipment.
Nutsedge thrives in wet soil and lots of sunlight. Having proper irrigation is the first step preventing nutsedge from growing. No over watering.
- Nutsedge thrives in water logged soil. An easy fix is to correct your irrigation and soil drainage problems.
- Prevent further tuber growth by removing the young nutsedge plants. Pulling the weeds will work fine, but it is most effective to hoe by hand.
- If tubers are present, repeated removal of top growth will help to keep them under control as it is essentially starving the plant. Note that mature tubers (nutgrass with more than six leaves) can sprout as many as 10-12 times! New sprouts will be weaker than the previous ones but they will gradually work together to resupply themselves unless removed.
- One of the best ways to avoid nutsedge in lawns in the first place is to cut high (good anyway for a lot of reasons). Cutting lower than 3 inches stimulates nutsedge growth.
What Does Not Work
- Using a tiller to destroy mature nutsedge. This technique will only cause the infestation to spread because it moves the tubers around in the soil, allowing them to resprout if they are strong enough. However, repeated tilling in small areas before the nutsedge matures will reduce populations
- Systemic herbicides, like glyphosate, are a common misplaced effort of destroying the plant but because the herbicides really only touch the leaves, the tuber remain unaffected. Glyphosate might work on the younger plant in which the tubers have not formed. Turf grass will absorb the glyphosate from reaching mature nutsedge, and possible damaging your turf grass.
- Black plastic mulching won’t do the trick as the sharp, pointy leaves will go right through.
For Garden Beds
For nutsedge in garden beds, try digging or pulling. Keep at it. Or spray or brush shoots with a kill-everything herbicide such as glyphosate (i.e. Round-Up). The glyphosate is okay in gardens because the nutsedge is easier to get to and more isolated. Exposure to garden plants, compared to turf grass is less likely to damage garden plants.
Then mulch or plant desired plants to keep nutsedge and other weeds from elbowing their way back into the bed.
Ryno Lawn Care is here to help manage your lawn and landscape. Call now for your free consultation. Nutsedge can be a battle of attrition. For a really bad nutsedge invasion in a lawn, it may be easier to kill off everything with glyphosate and reseed or re-sod from scratch.