Tall Fescue Establishment Is Affected by Seeding Dates and Growing Degree Days in the Northern Great Plains.

Tall fescue (Festuca arundinacea Schreb.) is a valuable cool-season turfgrass for lawns and sports fields. However, its use is limited in northern climates due to the risk of freezing damage. This research was conducted to determine the effects of seeding dates and growing degree days (DGG) model on tall fescue establishment in the Northern Great Plains. ‘Stonewall’, ‘Dynasty’, and ‘Grande II’ tall fescue, and ZEBA coated and uncoated ‘Turf Saver’ tall fescue and ‘Turf Blue’ Kentucky bluegrass (Poa pratensis L.) were seeded once a month during the growing season in 2009 and 2010. Tall fescue showed higher grass cover and higher turfgrass quality than Kentucky bluegrass at all seeding dates. Tall fescue seeded in May through July had 80% or higher grass cover by the end of the first growing season, while tall fescue seeded in late Aug. and Sept. covered less than 50% of the soil surface. Seedling emergence of dormant sown seed (8 Nov. 2010) was first observed in late April, 2011 and its grass cover was 25% by June, 2011. The result indicated that a successful establishment of tall fescue during the first year in the Northern Great Plains (≥ 80% grass cover) with no freezing damage can be accomplished when seeded before mid Aug. or after acquiring at least 1,000 accumulated air temperature-based GDD before the freezing temperature occurs.