Weed Sugar Content

Grass 

Sugar / NSC risk

Why

Bent grass

Higher

Bentgrass is a cool-season grass, and cool-season grasses tend to accumulate more NSC/fructans than warm-season grasses, especially in cool sunny weather. (DLF) (OSU Extension Service)

Dog’s tail grass

Higher to moderate

Dog’s tail is also a cool-season-type grass, so I would treat it as a potential sugar/fructan accumulator, especially during spring regrowth, fall regrowth, frost, drought, or sunny cool days.

Canary grass / Reed canary grass

Moderate to higher

Reed canary grass is a cool-season grass and one of the first grasses up in spring, so it can be a concern during active regrowth. (MN DNR)

Bluestem

Lower

Bluestem is a warm-season grass type. Warm-season grasses generally have lower NSC than cool-season grasses, though they are not automatically “safe.” (NJ Agricultural Experiment Station)

Johnson grass

Lower sugar concern, but higher toxicity concern

Johnsongrass is a warm-season grass, so it is usually not my first concern for sugar/fructan. But it has a separate livestock safety issue: under stress it can produce hydrocyanic/prussic acid. (extension.okstate.edu) (Noxious Weed Control Board)