What About Nutsedge?

With all the excess moisture we’ve been getting along the Eastern Seaboard, one of the weeds gaining a major foothold is nutsedge, or what some call nutgrass. These thick-bladed plants, lighter green than most lawn grasses, thrive in waterlogged soil and their presence often indicates that drainage is poor, irrigation is too frequent, or sprinklers are leaky. Once established they will tolerate normal irrigation conditions or drought.

The two most common species of nutsedge in are yellow nutsedge (Cyperus esculentus) and purple nutsedge (C. rotundus). They are true sedges and derive their name from small tubers that infiltrate the top six inches of the soil once the plants are established.

The key to control is understanding more about what the nutsedge is telling you about the soil — basically that it is seriously out of whack for growing grass. The soil likely has low levels of calcium and phosphate as well as high or excessive levels of potassium, magnesium, Iron, sulfate, boron, selenium, salts, and aluminum. Soils are also likely to have low humus and porosity, the presence of anaerobic bacteria.

The best remedy is to pull out the plants by hand if they are small. You may need to cover larger pages with rubber roofing underlayment or pond liner, or just dig them out entirely. The key is to get rid of the tubers. Generous applications of compost are essential to improve the drainage and get the beneficial bacteria in place. An application of high-calcium limestone or gypsum is usually beneficial.