Many ornamental grasses reproduce using runners. Those runners can easily grow under other plants to establish colonies of the grass in places that are less than ideal. Non-invasive ornamental grasses reproduce using very slow-growing runners that encourage the grass to clump without spreading to other areas of your lawn or garden. Clumping grasses are your best choice if you are concerned about an ornamental grass becoming invasive.
Switch grass is a non-invasive ornamental grass that, although it will grow in many types of soil, prefers a well-draining loamy soil. Switch grass is a fountain-like grass with billowy, feathery panicles that works well in borders or as an accent plant in rock gardens. The panicles can grow as much as 1 or 2 feet above the blades.
Golden Variegated Hakone Grass
Golden variegated hakone grass, or Hakonechloa macra, is a non-invasive Japanese forest grass native to Honshu that works well as an ornamental grass. Because it is a forest grass that in its natural environment would be shaded by taller forest trees, hakone grass grows best in shady locations. Hakone grass grows to between 12 and 18 inches tall and can often look like miniature bamboo. It grows best in rich, loamy soil that drains well.
Golden Variegated Sweet Flag
Golden variegated sweet flag is a non-invasive ornamental grass that can grow to between 3 and 6 feet tall. It grows well either in full sun or in partial shade. This grass does best in loamy soil that drains well but can also be tolerant of standing water. Its flowers are sweetly fragrant. The variegated blades of this tall grass can range from gold to creamy white or, in some cases, yellow.
There are two types of bamboo. One type reproduces via runners and can quickly become invasive. Clumping bamboo, however, is an ornamental grass that can help create visual interest in your garden. There are many varieties of clumping bamboo, ranging from 12- to 18-inch tall miniature bamboo to varieties reaching 10 to 12 feet tall. Some clumping bamboo has green culms, or canes, and others can have brown, golden, or even black culms.