Mexican Feather Grass In University of Tennessee Gardens, Knoxville in December

The ultra-fine soft foliage of Mexican feather grass (Nassella tenuissima) will grab your interest. Just a slight breeze will create wave movement in your garden (USDA hardiness zones 7 to 10). It grows 1½ feet high (2 feet tall in flower) and 1½ to 2 feet in width.

Mexican Feather Grass is a cool season grass native to dry rocky slopes and open grasslands from south central U.S. to Argentina. Established feather grass is highly drought tolerant. It thrives in full sun and average is well-drained soil. It grows poorly in either water-logged ground and in moderate shade.

Spring’s fine-textured foliage is lime-green followed by silvery-gold inflorescences in late spring. Summer’s heat and humidity causes this cool-season species to go dormant. Inflorescences age to a wheat-straw or blonde color. As temperatures cool down in the fall, Mexican feather grass goes through a second growth flush.

In the winter the foliage turns straw-colored, and plant form, texture and flowing habit all remain attractive. Cut back Mexican Feather Grass in late winter before spring’s growth flush begins. Mexican feather grass may re-seed, but is not difficult to manage.

Mexican feather grass performs well in rock gardens and xeric landscapes. It thrives planted in containers if not allowed to dry out. Its wispy threadlike foliage is attractive spilling over walls, boulders, or the edge of a container. Over time this vigorous grass tends to overwhelm most other perennials and annuals in mixed garden beds or containers.