Date of seeding affects establishment of cool-season turfgrasses

Little documentation exists on the success of seeding cool-season turfgrasses in the late fall, winter and spring. The objectives of these two studies were to document the success of seeding Kentucky bluegrass (Poa pratensis L,), perennial ryegrass (Lolium perenne L.), and tall fescue (Festuca arundinacea Schreb,) at less-than-optimum times of the year, and to determine if N and P fertilizer requirements vary with seeding date of Kentucky bluegrass, 'Ram I' Kentucky bluegrass, 'Fiesta' perennial ryegrass, and 'Mustang' tall fescue were seeded on 1 Sept., 1 Oct., 1 Nov., 1 Dec., 1 Mar., 1 Apr., and 1 May +/- 2 days beginning in 1989 and 1990, As expected, the September seeding date produced the best establishment, regardless of species. Dormant-seeding Kentucky bluegrass and tall fescue in November, December, or March reduced the establishment time compared with seeding in April or May. Seeding perennial ryegrass in November, December, or March may not be justified because of winterkill potential. To determine the effect of starter fertilizer on seedings made at different times of the year, 'Ram 1' Kentucky bluegrass was seeded 1 Sept., 1 Nov., 1 Mar., and 1 May +/- 2 days in 1989 and 1990, and the seedbed was fertilized with all combinations of rates of N (0, 24, and 48 kg.ha(-1)) and P (0, 21, and 42 kg.ha(-1)). Fertilizer rate had no effect on establishment regardless of seeding date, possibly because of the fertile soil on the experimental site.