Saturday, April 18, 2020

April is the best time to spot cheatgrass die-offs

Cheatgrass die-offs might sound alarming, but few people in the West are sorry to see cheatgrass gone. This exotic annual grass spreads into sagebrush grasslands where native shrubs and grasses are missing or weakened. When fire comes, dried cheatgrass burns readily and spreads fire among native plants, killing or damaging them. But when cheatgrass dies out in an area, seeds of longer-lived native plants can get started without competing with this invasive exotic grass.

Cheatgrass die-offs are easy to spot in April. For bonus points, you might also find the army cutworms that create them by eating each grass shoot as it comes up. The bare die-offs stand out against the surrounding cheatgrass, which is having a growth spurt in the warm temperatures and plentiful moisture of spring.

Die-offs can be almost completely bare, where native shrubs were killed by fire and cheatgrass moved in. These are an alarming sight.

Die-offs in areas with native shrubs (sagebrush and saltbushes) are a little harder to spot. You'll see shrubs without any herbaceous plants growing underneath them. The shrubs might be missing a good portion of their leaves, as they are here.

To find cheatgrass die-offs look for:

1. Bare areas where cheatgrass grew in previous years, with or without shrubs.

2. Sharp borders to bare areas, changing abruptly from bare soil to normal-looking cheatgrass.

3. Native shrubs, if present, missing most of their leaves: army cutworms also climb shrubs and eat leaves.

4. Gray-green larvae hiding during the day under cowpies and plant litter or in the soil.

If you find cheatgrass die-offs, seize the opportunity to seed native plants and revegetate these areas.