Date of seeding affects establishment of cool-season turfgrasses

Little documentation exists on the success of seeding cool-season turfgrass es 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 arund inacea Schreb,) at less-than-optimum times of the year, and to determine if N and P fertilizer requirements vary with seeding date of Kentucky bluegra ss, '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 Septembe r seeding date produced the best establishment, regardless of species. Dorm ant-seeding Kentucky bluegrass and tall fescue in November, December, or Ma rch reduced the establishment time compared with seeding in April or May. S eeding perennial ryegrass in November, December, or March may not be justif ied because of winterkill potential. To determine the effect of starter fer tilizer on seedings made at different times of the year, 'Ram 1' Kentucky b luegrass was seeded 1 Sept., 1 Nov., 1 Mar., and 1 May +/- 2 days in 1989 a nd 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 becaus e of the fertile soil on the experimental site.