Because Montana is located in the northern region of the United States, most of your cool season grasses will grow well in lawns and most notably Kentucky bluegrass and fine fescue.
Planting grass seed in Montana can be done between the months of spring and fall but keep in mind that planting in spring may give grass a longer growing season in which to get well established, but the summer heat and weeds may cause problems. Fall seeding minimizes danger of heat injury, but allow about 6 weeks of 50° F to 70° F. Lawns seeded within a week of Labor Day are more likely to fill in completely for winter and produce a thicker turf appearance for the following spring compared to lawns seeded in Fall. You want to plant your grass seed in the late summer because the warmer temperatures, accompanied with sufficient water, will encourage good grass seed germination.
A prime grass candidate for lawns in Montana is Kentucky bluegrass. It is considered the best quality turf grass for cooler climates and makes a fine textured lawn. It includes the ability to fill-in damaged parts without needing to reseed. Bluegrass is additionally a lot more winter-hardy compared to other cool season grass varieties. Newer varieties will be more resistant against diseases. It performs best in full sun, but could be mixed with a fine fescue to use in shady areas. Bluegrass might need one to three months to germinate and establish, based upon site conditions. It makes an outstanding athletic field. Bluegrass could be seeded or sodded for establishment.
Kentucky bluegrass planted in Montana is often blended with other cool season grasses like perennial rye grass. Its quick establishment time frame works well with the reduced establishment time of bluegrass. It’s also a fine textured grass much like bluegrass with good drought tolerance. Not necessarily as cold tolerant as bluegrass but can find a place in southern Montana lawns. Plant Kentucky bluegrass at 3 pounds per 1,000 square feet or 1.5 pounds per 1,000 square feet for over-seeding projects. Mow at 2 to 3 inches.
Fine fescue varieties are fine-leaved turf grasses that are suited well for conditions of shade, low soil moisture, low fertility, and soils with unfavorable pH levels. The fine fescues planted in sandy soils with good drainage grow best so adding a layer of sand on top of your soil surface during soil preparation can be effective. Extra applications of fertilizer, frequent irrigation or establishment on poorly drained soils can lead to a drop in quality and plant body. With ideal management, the fine fescues could make an attractive turf for your lawn. Fine fescues are seldom seeded by itself. Fine fescues are commonly found in mixtures with the other cool-season turf grasses on low maintenance or shady lawns. Plant at 5 pounds per 1,000 square feet and maintain mowing height between 3 and 4 inches.