Because Oregon is located in the northern region of the United States, most of your cool season grasses will grow well in lawns and in fact many Oregon farmers are major producers of all cool season grass varieties for seed production. So you can’t go wrong with planting a Kentucky bluegrass, tall fescue, fine fescue, or even a perennial ryegrass variety. Some areas of Oregon, like the Willamette valley, actually use bent grass in some of their lawns.
Planting grass seed in Oregon 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. Avoid planting in summer and spring. 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.
Kentucky bluegrass 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 Oregon is often blended with other cool season grasses like perennial rye grass. Its quick seed germination works well with the slower 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 be a nice fit in some areas of Oregon. 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 a thinning lawn. 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.
Below are some general seed mixtures for different regions of Oregon.
West of the Cascades (sunny areas)
Mixture 1: 70-80 percent perennial ryegrass blended with 20-30 percent fine fescue.
Mixture 2: 25-50 percent perennial ryegrass blended with 50-75 percent Kentucky bluegrass.
Mixture 3: 50 percent perennial ryegrass mixed with 25 percent Kentucky bluegrass and 25 percent fine fescue.
You Got Shade?
Mixture 1: 70 percent fine fescue blended with 30 percent perennial ryegrass.
Mixture 2: 60 percent fine fescue mixed with 20 percent perennial ryegrass and also 20 percent bluegrass.
East of the Cascades (sunny areas)
Mixture 1: 75 percent Kentucky bluegrass blended with 25 percent fine fescue or perennial ryegrass.
Mixture 2: 50 percent perennial ryegrass mixed with 25 percent Kentucky bluegrass and then 25 percent fine fescue.
Mixture 3: 100 percent tall fescue.
You Got Shade?
Mixture 1: 50-75 percent fine fescue mixed with 25-50 percent Kentucky bluegrass.
For step-by-step instructions on soil preparation and planting grass, visit the Planting Grass Seed page.