Yellow and purple nutsedge are technically not grasses, they are graminoids or grass-like plants that flower which fall under the sedge family. Although there are some reasons to grow certain types of sedges for the edible tubers found underground the most common sedges found in residential lawns are well known to be some of the world’s most problematic weeds.
In many locations these weeds are classified as invasive meaning it’s particularly important to do what we can to control their spread.
These tufted grass-like plants are often called nutgrass or sedgegrass; they grow in wet, marshy soils or well irrigated lawns and are recognized by their triangular stems and inconspicuous flowers.
Once nutsedge gets into your lawn, it is difficult to control because of its extensive root system. Nutsedge roots grow 8 to 14-inches down into the soil and form tiny tubers or nutlets. These nutlets are how nutsedge reproduces, along with its rhizomes and seeds, and are why nutsedge is hard to control. A heavy nutgrass population can take more than one season to eradicate from your lawn.
Therefore, the best way to stop nutsedge in your lawn is to prevent it from taking hold in your grass in the first place or getting rid of it quickly once it’s noticed. It’s much easier to focus on prevention rather than trying to eradicate it once it’s out of control.
1. Prevent Nutsedge Seed Germination – Apply a preemergent product to the lawn early in the spring before nutsedge seeds germinate.
2. Maintain a healthy lawn – Test your soil for pH and nutrient content and apply fertilizers and other amendments based upon the test recommendations to provide optimal nutrient content.
3. Water Deep & Infrequently – Water lawns only when moisture is needed to prevent over-watering. Water infrequently, giving the grass more water in a single event, instead of watering a little bit every day.
4. Improve Soil Aeration – Aerate and/or dethatch your lawn routinely to improve soil drainage and the movement of water, air, and nutrients through the root zone.
5. Mow grass at the recommended height – Routine lawn mowing at standard heights will support thick turf and make it harder for sedges to infiltrate your lawn.
6. Insect Control & Prevention – Manage nuisance insects and disease problems to prevent thin or bare spots in the lawn.
7. Physically Remove Young Sedge Plants – Identify young plants and pull (or dig) them out before they start forming tubers.
8. Maintain & Clean Your Equipment – Thoroughly clean tools and equipment (rototiller, tractor tires, shovels) after they are used in infested areas to avoid transferring small pieces of the tubers and rhizomes to your lawn.
9. Only Buy Products From High Quality Sources – Check any incoming products to make sure you aren’t unknowingly bringing tubers into your yard. The most common culprits are potting soil, fill dirt, mulch, and container plants.
Herbicides can be used but should be turned to as a last resort. These weed-killing chemicals don’t effectively control mature nutsedge or tubers, and they only have a limited effect on young nutsedge plants. If you opt to use an herbicide, make sure to choose a product suited for the type of nutsedge in your lawn (yellow or purple), and follow the label directions carefully.