Creeping bentgrass seed germination in growth chambers at optimal and suboptimal temperatures

Turfgrass managers attempting to establish creeping bentgrass (Agrostis stolonifera L.) from seed following winterkill episodes may benefit from cultivars that germinate and establish quickly during cold temperature periods. The purpose of this study was to identify the percentage and time until germination of different cultivars of creeping bentgrass under a suboptimal temperature regime. Twenty-seven seed samples showing ≥90% germination under the optimal temperature regime of 77:59 °F on an 8:16-hour light–dark cycle were selected for germination tests at the suboptimal temperature of 50 °F on an 8:16-hour light–dark cycle. The results show differences among creeping bentgrass samples with respect to cumulative germination percentages (CGP) and days to germination when incubated at 50 °F. Seed samples of ‘Pure Select’, ‘Penn A’-4, ‘Crystal BlueLinks’, and ‘007’ were most consistent with respect to high germination percentages and days to germination at 50 °F. However, where multiple seed samples of the same cultivar were examined, variation in CGP and days to germination were detected among samples. Cultivars with superior germination characteristics at low temperatures may improve creeping bentgrass establishment from seed following winterkill episodes. However, practitioners should be aware that germination at low temperatures may vary among seed samples or seed lots of individual cultivars because of factors associated with seed vigor, such as seed age, preharvest environmental conditions, seed storage methods, and other factors, which could result in variable rates of establishment in early spring.