Remove nutgrass, including the subsurface nut, on a weekly basis to prevent it from going to seed or multiplying. (The nut is edible. You can roast and toast them. It was the snack food of the ancient Pharaohs).
Plant competitive plants to deprive it of sunlight, moisture, and nutrients. Avoid over watering and mulch heavily to slow growth and improve the soil.
Nutgrass likes tight, waterlogged clay soils. Consider regrading the affected area with topsoil.
Consider planting sweet potatoes. The vines form a dense cover and release a chemical which inhibits nutgrass.
Avoid hoeing nutgrass as this practice will not help achieve long term control.
