How to Kill Sedge Grass
Sedge grass in your lawn, garden or flowerbeds is unattractive and difficult to kill. Sedge grass cannot be pulled out because it reproduces underground and will grow back. Oftentimes general chemical weed killers do not do the trick and are detrimental to your soil's health.
As an alternative, sedge grass can be safely eliminated using organic methods.
Cut the sedge grass off at its base. Keep the grass cut as it grows as this will help choke the rhizomes and prevent nutrient absorption.
Pour boiling water into the soil so it scalds the roots of the sedge grass. Be careful with boiling water as it can damage plants around the sedge grass.
Apply vinegar-based weed killer to the sedge grass. The acids in vinegar will attack the plant. There are many brands of vinegar-based weed killers available. Follow the directions on the container. Be careful with vinegar weed killer, as it too can damage plants surrounding the weeds.
Sprinkle an even layer of sugar over your entire lawn, garden or flowerbeds. Sugar will fortify the nutrient-holding micro-organisms in the soil. As a result, it becomes difficult for the weeds to access those nutrients. Without access to soil nutrients, sedge grass will eventually die off. Mix an equal part of chilli pepper in with the sugar if there is a concern about attracting pests.
Sprinkle extra sugar around the bases of the sedge grass plants.
Water the ground just enough to dampen it slightly.
Apply sugar to the sedge grass every two to three days. You should be able to see the sugar starting to work in about two weeks.
Begin using only organic fertilisers such as manure compost, corn gluten or alfalfa meal in order to keep your soil healthy. Organic fertilisers will keep the soil healthy and nutrient rich. It is much easier to keep weeds away if you have healthy soil.