Nutsedge

Overview

Nutsedge (Cyperus spp.) is not a grass — it is a sedge, identifiable by its triangular stem cross-section (“sedges have edges”). It is one of the most persistent lawn weeds due to its underground tuber network, which can extend over a foot deep and remain dormant in soil for years.

Identification

Bright yellow-green, upright blades that grow noticeably faster than surrounding turfgrass — sticking up 2-3 days after mowing. Roll the stem between your fingers: if it feels triangular rather than round, it is nutsedge. Yellow nutsedge and purple nutsedge are the two main species.

Damage to Your Lawn

Nutsedge competes through root competition. Its underground tuber and rhizome network reaches well below the grass root zone, stealing moisture and nutrients. A single plant can produce 1,900 tubers in one growing season. This makes nutsedge one of the most aggressively spreading weeds.

Why Pulling Makes It Worse

Underground tubers snap off when you pull. Each broken tuber left in the soil becomes a new plant. Pulling can actually increase the nutsedge population by fragmenting the tuber network and stimulating dormant tubers to sprout.

Control Strategy

Halosulfuron-methyl (Sedgehammer/Empero) is the only reliable chemical control for homeowners. Plan on 2-3 applications spaced 6-10 weeks apart because tubers keep sending up new shoots after each treatment. Requires non-ionic surfactant.

Cultural control: Improve drainage. Nutsedge thrives in persistently wet soil. Reduce irrigation frequency and promote dense, healthy turf to suppress emergence.