Mexican feather grass
Nassella tenuissima · Poaceae Popular
The finest-textured grass: hair-thin, bright green leaves and silky, blond flower heads that ripple like water in the slightest breeze.
- Size
- 20 in tall, 18 in wide
- Zones
- 7 to 10
- Light
- Full sun
- Flowers
- Early June to late July
- Pets
- No toxicity recorded
- Job in a bed
- Weaver
A bed built around Mexican feather grass
The planner designed this bed around Mexican feather grass when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting in zone 7, full sun. It chose the other plants from the 721 that suit those conditions and its dry soil, and says below why Mexican feather grass stands where it does.
The plants
- 1 Mexican feather grass × 2, tan
- 2 Sedum 'Lidakense' × 34, pink
- 3 Sea thrift × 7, white
- 4 Stiff goldenrod × 5, yellow
- 5 Foxglove beardtongue × 3, white
- 6 Dwarf English boxwood × 1, dark green leaves
- 7 Pineapple lily × 2, purple
- 8 Saffron crocus × 12, purple
Why this plant
- Part of the matrix. The low fabric of grasses and groundcovers that the taller plants come up through.
- The only plumes. The others are dense clusters, globes, flat plates and others. Shape reads at a distance, where colours blur.
- The only tan. Tan sits between stronger colours and calms them.
Why here
- In the middle. At 20 in it is the step between sea thrift (8 in) in front and foxglove beardtongue (3½ ft) behind: each is seen over the one before.
- 2 plants in 2 places. An accent is a punctuation mark: the repeat along the bed gives it rhythm.
- Fine leaf against bold. Stiff goldenrod is beside it: the strongest contrast of leaf there is.
Why now
- In flower for 8 weeks. From early June to late July.
- Fills a gap. For three of those weeks nothing else on the plan is in flower.
- Stands through winter. Left uncut, it holds its shape until March, when the perennials have gone.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 52% of the planted ground. Dwarf English boxwood is grown for its leaves rather than its flowers. The flowering is at its height from early June, with 3 kinds out together.
The planner's own design check: 11 Excellent, 5 Good, 1 Satisfactory. It flags one thing to watch: Mexican feather grass spreads aggressively. Each plant's details say more.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where Mexican feather grass goes in a border
At 20 in it belongs in the middle of a bed. In the planner's ten height classes it is medium short (18 to 24 in).
Its job: weaver. A light, airy plant threaded singly between sturdier ones to knit the planting together.
Nothing moves like it. Thread single plants between perennials in a gravel garden. It seeds very freely in mild climates, so check local advice first.
- Movement in dry, sunny gardens
- Softening paving and gravel
- Containers
What to plant with Mexican feather grass
Plants recorded as good partners for it, and what each pairing does:
- Autumn sage: in flower together for eight weeks, from early June; happy in the same dry soil.
- Russian sage: in flower together for three weeks, from mid July; tall enough (4 ft) to stand behind it; happy in the same dry soil.
- Blanket flower: in flower together for seven weeks, from mid June; happy in the same dry soil.
Questions about Mexican feather grass
Does Mexican feather grass need sun or shade?
Mexican feather grass grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.
What zones does Mexican feather grass grow in?
USDA zones 7 to 10. It is hardy to zone 7, which means it survives winter nights down to about 10 °F (−12 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does Mexican feather grass flower in my zone?
In zone 5 it flowers early June to late July. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 7 | Late May to mid July |
|---|---|
| Zone 8 | Late May to mid July |
| Zone 9 | Late May to mid July |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should Mexican feather grass be planted?
16 in (40 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 18 in (45 cm), so a group knits into one patch.
It grows 20 in (50 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many Mexican feather grass plants do I need?
At 16 in apart, set out in staggered rows:
- 7 to fill 10 square feet (about 1 m²)
- 8 for a single row 10 ft (3 m) long
- 21 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, threaded between sturdier plants.
In the bed above, the planner used two in two groups.
Is Mexican feather grass poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat Mexican feather grass?
Mostly not. NC State lists it as resistant to deer. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
Will Mexican feather grass spread?
It seeds itself about; the risk of it taking over is high. Self-seeds very freely in mild, dry climates and has escaped from gardens in California. Do not plant it near wild land there, and cut off the seed heads before they ripen.
What flowers after Mexican feather grass?
Mexican feather grass is over by late July. These start as it finishes and carry the same spot on, so it never goes flat:
- Lilyturf: from early August to mid September, 16 in tall.
- Ornamental onion 'Millenium': from mid July to late August, 18 in tall.
- Black-eyed Susan 'American Gold Rush': from mid July to early October, 24 in tall.
What does Mexican feather grass look like in winter?
Mexican feather grass holds some of its leaves into winter, more in a mild year or a sheltered spot, and they look tired by March. Cut the old ones off as new growth starts.
In these guides
Every fact on record
- Type
- Grass
- Size
- 20 in (50 cm) tall, 18 in (45 cm) wide
- Plant
- 16 in (40 cm) apart
- Height class
- Medium short (18 to 24 in)
- Place in the bed
- Middle
- Flowers
- Early June to late July; feathery plumes; tan
- Leaves
- Fine texture, semi-evergreen; green
- Shape
- Arching, self-seeding
- Hardy in
- USDA zones 7 to 10
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Poaceae
- Comes from
- South Central U.S.A. to Mexico and Argentina
- Stands up to
- Deer, drought, erosion
Checked against NC State Extension. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.