Needlegrass, or achnatherum occidentale, is native to western North America. Its range stretches from Canada through the western United States. Needlegrass is a bunching grass, meaning each seed produces a clump of blue-green, erect foliage with bronzy seed heads. It can be used for grazing and erosion control in its native range; however, it is not typically used in gardens as an ornamental grass. The only variety of needlegrass available is the wild species; no cultivars (hybrids) have been developed. While it is a beautiful tall grass, needlegrass tends to blend into the background, failing to give the height and structure other ornamental grasses bring. It has a tendency to fade in late summer when its foliage turns brown. Use needlegrass in meadow or prairie plantings where it works as a backdrop for native wildflowers such as daisies, asters, lupines, sunflowers and ironweed.
Choose a spot in full sun with well-drained but moisture-retentive soil. Needlegrass tolerates a range of pH but prefers alkaline or sweet soils over acid soils.
Remove the top 2 to 3 inches of turf and topsoil the year before sowing needlegrass. Removing turf and topsoil is a quick way to eliminate grass and weeds. A shovel works for small areas, just make vertical cuts with the shovel, then angle the shovel at 45 degrees to remove a strip of soil and grass. For large areas, use a turf remover.
Cover the planting area with 2 to 4 inches of compost. Till into the top 4 to 5 inches of soil.
Place several sheets of black plastic over the exposed area. Black plastic excludes sunlight and heats the ground sufficiently to "cook" the seeds, effectively killing the embryo. Use concrete blocks, scraps of wood or bricks to weight the plastic sheets and prevent them from blowing off. The black plastic should remain in place until you are ready to sow the needlegrass seeds.
Remove the black plastic and gently rake the planting area smooth. Do not disturb the soil more than 1/2 inch down. Doing so will bring weed seeds to the surface. This step should be done the same day you sow needlegrass seeds.
Sow needlegrass seed in late summer to early fall. Mix the seed with moistened sand to make it easier to sow and to prevent seed from blowing into areas you don't want it.
Broadcast the seeds over the planting bed. As a general rule, use 7 pounds of seed per acre to be seeded if you want a pure needlegrass stand.
Water your needlegrass only in prolonged periods of drought. Give the needlegrass planting 1 to 2 inches of water a week.
Mow your needlegrass stand to the ground in early spring before you see signs of emerging growth. Mowing keeps the needlegrass looking neat and allows you to appreciate the emerging stands.