Tall Fescue

Biology

Tall Fescue, a perennial grass, serves as a desirable lawn species when using improved cultivars, but it becomes undesirable when forage tall fescue plants contaminate other primary species in a lawn. For those interested in botanical details, there’s been a lively debate recently about the scientific name of tall fescue. Although it has been known by one scientific name for over 60 years, scientists are now formally classifying it as Schedonorus arundinaceus.”

Identification

Tall fescue, known for its coarse texture and wide blades, is a bunch-type grass. Recent improvements in tall fescue leaf texture have led to the development of more fine-bladed varieties or cultivars. These advances have increased the turf quality and boosted its use as a drought-tolerant turf in Indiana. We often recommend these improved turf-type varieties of tall fescue as the primary choice for lawns. However, older, wider-bladed, forage-type varieties like Kentucky tall fescue still exist and can become problematic weeds.

Cultural control

When there are few weedy patches of bunch-type grasses like tall fescue, it is best to cut them out with a shovel or knife. Be sure to cut down a couple of inches into the soil to get all the stems. Refill the holes with soil and seed immediately with the desirable turf species similar to the existing turf.

Biological control

None known.

Chemical control

“If you’re dealing with a large number of tall fescue plants, chemical control becomes more efficient. You can spot-apply a nonselective herbicide like glyphosate (found in products such as Roundup) to target these plants. However, be cautious, as these herbicides also kill surrounding desired turf species. Treat only the tall fescue clumps. You might need two applications for complete control. After the final application, wait 7 to 14 days before reseeding the area.

Chlorsulfuron (previously sold under the brand name Corsair) was a selective herbicide used to control tall fescue in various turf species. Although Corsair is no longer on the market, some existing stocks might still be available. Products like Telar XP and Chlorsulfuron 75DF, containing the same active ingredient as Corsair, are suitable for use on turf in industrial sites and roadsides but not in managed turf areas like golf courses, lawns, and athletic fields. Follow the label instructions carefully when spot applying chlorsulfuron.

To manage tall fescue in warm-season lawns and athletic fields, apply a nonselective herbicide like glyphosate in late winter when bermudagrass is dormant. Alternatively, consider using sulfonylurea herbicides. Many of these are labeled for selectively removing cool-season grasses, including tall fescue, from bermudagrass and zoysiagrass.”