Grass Species And Varieties For Severe Winter Climates (P6)
7. Rough meadow grass (Rough bluegrass) (Poa trivialis)
Some Scandinavian greenkeepers have used this species to re-establish dead Poa greens in the spring. It germinates fast, but persistency in greens has been poor under our conditions. The varieties on the market were developed for overseeding and winter play on Bermuda greens in the southern United States and Mediterranean areas, not for Nordic climates.
8. Perennial ryegrass (Lolium perenne)
This is not one of the main grass species on Nordic golf greens, but is used as a first aid species to re-establish greens after winter kill. The genetic variations in winter survival among the many varieties of ryegrasses are relatively small. It will probably take time to produce varieties that can both be classified as winter tolerant and with acceptable playing quality. Tetraploid ryegrasses are more resistant to snow moulds; they can be used on fairways, tees and roughs but they will not produce acceptable density at green’s mowing height.
9. Annual meadow grass (Poa annua)
Very few commercial varieties have been tested in the Nordic countries and the winter stress tolerance has been very poor, both when it comes to ice encasement and pink snow mold. Most studies agree that the best freezing tolerance (LT50) than can be achieved is in the range -10 to -14 °C. According to Canadian studies, there is, however, significant variation in winter hardiness among local ecotypes of annual meadow grass. The best ones may have winter survival superior to the best varieties of perennial ryegrass. Coastal and southern golf courses in the Nordic countries often have acceptable survival of annual meadow grass after use of fungicides in autumn.