The thick, long-lasting foliage of tall ornamental grass is perfect as a privacy screen from the neighbours or as a living wall between the yard and a road. The grass can hide compost bins, heat pumps or transformers while showing off long narrow leaves and feathery flowers. As a breeze blows through the tall grass, the gardener hears the gentle swishing of leaves together, dimming the noises from outside the landscape.
Plant tall ornamental grasses as far apart as they will be tall. Mounding grasses need a little more space while narrow upright types can be a little closer together. Average soil is fine for most varieties, but adding compost or other organic matter to the soil is always beneficia. Most ornamental grasses prefer full sun. The grasses seldom require extra watering once they are established and need no fertiliser.
Perennial grasses spread through underground roots called rhizomes. These thick, tough roots can help control erosion on slopes and in areas of flooding. The root system of ornamental grass can be running rhizomes that expand quickly to cover a large area or a clumping type which slowly increases the width of their clump.
When a stand of tall ornamental grass starts looking crowded, use a sharp spade to cut the roots into sections. Pry these apart with a knife or spading fork and replant the sections in new areas of the landscape. Division of all type of ornamental grasses can be done in early spring before new growth begins.
Arundo donax Variegata is a tall ornamental grass suited for landscaping. Commonly called variegated giant reed, this stunning grass grows 7 feet or more and has 1-inch diameter stems. It has corn-like leaves striped green and white. It can be grown in USDA Hardiness Zones 6 through 10. Big bluestem (Andropogon gerardii) grows in tall, narrow columns to 6-feet. The foliage turns russet in autumn but is a blue-green colour all summer. It likes zones 4 through 10. Stems 9-feet tall with feathery plumes rise above grey-green foliage on the clumping ravenna grass (Saccharum ravennae). Surviving in zones 6 through 10, it also puts on a fall show as its thick foliage turns to bronze.
Any grass has the potential of becoming invasive. The types with running root systems are more of a problem to control because they spread quickly. Each region may have problems with a different grass, so check with the local agricultural extension offices or local weed control boards to see which varieties may be considered noxious weeds in the local environment even though they may appear beautiful.