How to Grow Mexican Feather Grass

The pros and cons of a popular ornamental grass

Mexican feather grass plant with long tan blades blowing in wind

The Spruce / Evgeniya Vlasova

Mexican feather grass has its pros and cons. On the plus side, its stems have a delicate beauty—they grow to about 2-feet tall—a beauty enhanced when they sway gracefully in the wind with its feathery flower panicles. But its benefits are practical as well as aesthetic since this moderate-growing ornamental grass is drought-tolerant once it matures. Mexican feather grass seedlings do best when planted in the spring.

On the negative side, Mexican feather grass is invasive in some regions. In regions where the plant is invasive, growing Mexican feather grass requires a great deal of landscape maintenance because you will need to continually remove the seedlings from spots in your yard where you do not want them growing.

Botanical Name Nassella tenuissima (formerly, Stipa tenuissima)
Common Name Mexican feather grass, Mexican feathergrass, Mexican needle grass, Mexican wiregrass, pony tails, silky thread grass, Texas tussock
Plant Type Perennial ornamental grass
Mature Size 24 in. tall, with a slightly greater spread
Sun Exposure Full sun to partial sun
Soil Type Loamy
Soil pH Slightly acidic to slightly alkaline
Bloom Time Mid-summer
Flower Color Begins greenish, matures to a golden-brown, fades to a tan 
Hardiness Zones 7-10 (USDA)
Native Area South America, Central America, parts of the American Southwest

Mexican Feather Grass Care

The dense, fountain-shaped clumps of Mexican feather grass stems have a fuzzy appearance; they soften hardscape features in the landscape and make them more welcoming. For this purpose, it is especially effective to grow several of the plants in a line to form a border (for example, along a patio). Its light color (the leaves are a silvery green to lime-green) makes it a good foil for darker plants, for which the plant can be used as a backdrop. It is also a good plant to use in borders for cottage gardens.

Although Mexican feather grass does flower, treat it as you would any other foliage plant, complementing it with flowering plants. As a plant primarily grown for its foliage, it offers visual interest across multiple seasons, including even into winter. In zones 7-10, it goes dormant in winter, but the dried stems remain behind. When treated as an annual north of zone 7, this ornamental grass, even though it is dead, furnishes some winter interest.

The plant is not often bothered by diseases or insect pests, although aphids and leaf spot occasionally plague it. Deer and rabbits tend to leave it alone.

Many homeowners with slopes to plant choose to grow Mexican feather grass because it is helpful in controlling erosion.

Invasive Species

Detracting from its usefulness is the fact that Mexican feather grass is an invasive plant in certain parts of the United States (in California, for example, where it is also a fire hazard), even though it is native to other parts of the United States (New Mexico and Texas). Check with your local county extension before planting it to see if it is invasive in your particular region.

Mexican feather grass with wispy green and tan blades closeup

The Spruce / Evgeniya Vlasova

Mexican feather grass with tan blades

The Spruce / Evgeniya Vlasova

Mexican feather grass with tan blades clustered in front

The Spruce / Evgeniya Vlasova

Mexican feather grass with green blades and tan plumes closeup

The Spruce / Evgeniya Vlasova

Light

While the plant can survive in partial sunlight, Mexican feather grass performs best in full sunlight.

Soil

Plant Mexican feather grass in a loamy soil, since it needs good drainage. If your present soil is not loose enough, loosen it up by working some sand and organic matter into it.

Water

Mexican feather grass has low-to-average water needs. Once established, it is drought-tolerant: Mexican feather grass copes with droughts by going into dormancy.

Temperature and Humidity

Mexican feather grass isn't a great lover of hot summery weather: It doesn't die out, but it tends to lose its color in the warmest, most humid months.

Fertilizer

Fertilize Mexican feather grass annually with a good layer of compost.

Pruning

Mexican feather grass doesn't really need pruning, but you may want to trim away dead flowers and overgrown stems at the end of the season so you tidy them up for dormancy. Use a clean, sharp garden shear and make sure to clear away the debris so that the detritus doesn't accidentally reseed.

Propagating Mexican Feather Grass

Mexican feather grass can be propagated by division, done in the spring before your grass sends up any new shoots of growth. To do: gently dig up your clump of grass with a clean shovel and trowel. Use a clean, sharp garden spade to split the plant into three. Replant and water well.

How to Grow Mexican Feather Grass From Seed

Nassella tenuissima does well when planted from seed if you start your seeds indoors in the early spring. Place on a layer of potting mix, then cover with a thin layer of the same potting mix, soil, or sand. Water regularly; plant outside when sturdy.

Potting and Repotting Mexican Feather Grass

You can also grow Mexican feather grass in a large container, mixed with other plants. Give its height, it is most effective as the central plant in such a mixed planting. Surround it with shorter plants that enjoy full sun and sharp drainage. Be especially careful to avoid overwatering Mexican feather grass when it is being grown in a container.