Optimal ratios between Chewings fescue and slender creeping red fescue in seed blends and mixtures for golf course putting greens

Abstract Red fescue (RF, Festuca rubra L.) is one of the most widely used turfgrass species in Europe. The subspecies Chewings fescue (CF) and slender creeping red fescue (SlCRF) are used on putting greens because they tolerate a mowing height of 4–5 mm. Previous research has shown CF to be more winter‐hardy than SlCRF, however, SlCRF has a greener winter color. Our objective was to find the optimal weight ratio of the two subspecies in seed blends for greens in contrasting climatic regions of the Nordic countries. Musica and Cezanne (reference varieties in SCANGREEN variety testing since 2012) were selected as representatives for CF and SlCRF, respectively. Seed blends including CF/SlCRF in weight ratios of 75/25, 50/50, and 25/75 were compared to pure CF and SlCRF at Sydsjælland GC, Denmark, NIBIO Landvik, Norway, NIBIO Apelsvoll, Norway, and Reykjavik GC, Iceland as an add‐on to SCANGREEN variety testing 2015–2018. Results showed the optimal blends to produce higher turfgrass quality and tiller density than monocultures of either subspecies at all sites except Apelsvoll where plots were killed during the first winter. The best‐performing CF/SlCRF blend was 50/50 at Sydsjælland and Landvik and 75/25 at Reykjavik. While this shows seed blends to have advantages compared with the pure subspecies, the study should be repeated with a focus on dollar spot ( Clarireedia spp.), which has become a major turfgrass disease in Southern Scandinavia since these trials were conducted.