Putting Green Reestablishment Following Winterkill

Reestablishing cool‐season turfgrass following winterkill can be difficult because of below‐optimum temperatures in the spring. The research objectives were to determine the effects of fertilizer program, cover, and seeding creeping bentgrass ( Agrostis stolonifera L.) or annual bluegrass ( Poa annua L.) on putting green reestablishment. Research was conducted at the Hancock Turfgrass Research Center (HTRC), East Lansing, MI. Winterkill was simulated by applying a nonselective herbicide to a different creeping bentgrass putting green in each year. ‘Penn A‐4’, ‘Providence’, and ‘Alpha’ creeping bentgrass were seeded at 10 g m −2 . Annual bluegrass florets were applied at a rate of 2500 florets m −2 . A 0.1‐mm clear polyethylene cover or a noncovered control were initiated at seedling emergence. The fertilizer treatments were urea applied at 5 g N m −2 every 7 d or a starter fertilizer applied at 15 g N m −2 every 21 d. Turfgrass cover was rated visually on a scale from 0 to 100%. There were significant differences between annual bluegrass and creeping bentgrass cultivars. Annual bluegrass had the lowest percentage turfgrass cover on all dates. There were significant differences among creeping bentgrass cultivars on two dates and between fertilizer programs on two dates. There were no significant cover treatment effects in 2007. On three dates in 2008, the polyethylene cover resulted in 3 to 6% higher turfgrass cover than the uncovered treatment. Seeding annual bluegrass florets was not an effective method for reestablishing putting greens, and there was limited benefit from using protective covers to improve establishment rate.