Botanical composition of tall fescue-Kentucky bluegrass turfgrass mixtures is sustained in long-term study

Turfgrass mixtures composed of tall fescue and Kentucky bluegrass are common in transition-zone environments. However, it is unclear if the botanical composition of these mixtures is stable over time. The objective of this study was to evaluate the evolution of botanical composition of four tall fescue/Kentucky bluegrass mixtures subjected to three different mowing heights (20, 32, or 62 mm) over a five-year period. A field study was conducted at the Experimental Farm of Padova University (Italy). Four turfgrass mixtures composed of tall fescue and 'Nublue Plus' Kentucky bluegrass were seeded in September 2010. Tall fescue cultivars were considered either rhizomatous types ('Rhambler SRP, 'Traverse SRP'), or traditional, non-rhizomatous types ('Lucky Selen' and 'Lexington'). The percentage of each species in the mixtures was evaluated each spring from 2011 to 2015. The mixtures with rhizomatous tall fescue proved to be better in sustaining a balance with the Kentucky bluegrass. Kentucky bluegrass became more dominant in the mixtures containing the non-rhizomatous tall fescue cultivars and at high mowing heights.