Answer: Nutsedges thrive in moist areas and their presence often indicates that drainage is poor, irrigation is too frequent, or sprinklers are leaky. Once established, however, they will tolerate normal moisture levels or even drought.
Control of nutsedge should be viewed as a long-term process. Pulling the plants out by hand is relatively ineffective because tubers deep in the ground usually break off the pulled shoots. Very young plants can be controlled by hand weeding or hoeing if they are consistently weeded out before they have five to six leaves. In summer this will require weeding at least every two to three weeks, but doing so will cause a depletion of energy reserves and resprouting will soon stop. Once nutsedge plants have more than five or six leaves, they begin to form tubers, usually in May or June. Mature tubers can resprout as many as 10 to 12 times.
Using a tiller to destroy mature plants will only spread the infestation, as it moves the tubers around in the soil. However; repeated, frequent tilling of small areas before the plants have six leaves can gradually reduce populations. Tilling for nutsedge suppression should be limited to times when the soil is dry. Tilling when soil is wet is more likely to move tubers into new areas, as they adhere to equipment.
It is possible to eliminate very small patches of nutsedge by digging. Dig at least 10 inches deep and at least eight to 10 inches beyond the diameter of the aboveground leafy portion of the plant. This will ensure removal of the spreading tubers. Removal by digging is best done early in the spring, before more tubers are produced.
Since nutsedges do not grow well in shade, areas of the vegetable garden can be rotated into a solidly planted, dense, relatively tall crop such as beans or southern peas for a season. This will reduce the amount of nutsedge in the garden over several seasons. Or, you can cover the entire bed with weed barrier cloth and cut slits or X's for each of your plants. The weed barrier will keep the nutsedge from sprouting.
As a last resort, Glyphosate (Roundup Super Concentrate, Eraser, Glyphomax, Glypho, and others) can be used to control nutsedge in vegetable gardens. Glyphosate will damage or kill crop plants if it touches their foliage. Care must be taken to avoid damaging plants with spray drift. Repeat applications as new plants emerge.
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