How far apart should I plant Mexican feather grass?

About 40 cm (16 in) apart, centre to centre. A mature plant spreads 30–50 cm (12–20 in).

Does Mexican feather grass need full sun?

Full sun: at least 6 hours of direct sun a day.

How much water does Mexican feather grass need?

Low water. Drought tolerance is high and waterlogging tolerance none.

How cold-hardy is Mexican feather grass?

It tolerates about -17 °C (1 °F) once established, roughly USDA zone 7.

When does Mexican feather grass flower?

From about June for 9–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones).

Is Mexican feather grass poisonous to cats and dogs?

For cats it is mildly toxic; for dogs mildly toxic; for people not known to be toxic. Not chemically toxic, but sharp awned seeds can injure the eyes, skin and mouths of dogs, cats and grazing animals.

What grows well with Mexican feather grass?

There is no well-documented companion pairing for Mexican feather grass. Group it with plants that like the same sun (full sun) and water (low).

Mexican feather grass Nassella tenuissima

Mexican feather grass (Nassella tenuissima) is an evergreen perennial grass in the Poaceae family, native to Southwestern United States, Mexico and Argentina. It grows 40–60 cm (16–24 in) tall and 30–50 cm (12–20 in) wide, wants full sun and low water, and is hardy to about -17 °C (1 °F). Space plants about 40 cm (16 in) apart.

Plan Mexican feather grass in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.

Mexican feather grass at a glance

Type	Perennial grass, evergreen
Family	Poaceae
Mature height	40–60 cm (16–24 in)
Mature spread	30–50 cm (12–20 in)
Spacing	40 cm (16 in) centre to centre
Sun	Full sun, at least 6 h of direct sun a day
Water	Low; drought tolerance high, waterlogging tolerance none
Soil pH	6–8
Cold hardiness	About -17 °C (1 °F) once established (roughly USDA zone 7)
Heat stress	Likely above about 35 °C (95 °F)
Flowering	from about June for 9–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones)
Wind tolerance	Moderate
Pollinator value	None
Edible	Not grown as food
Native to	Southwestern United States, Mexico and Argentina
Common in gardens of	🇲🇽 Mexico, 🇺🇸 United States, 🇬🇧 United Kingdom
Invasive in	Australia (declared weed in several states), New Zealand (National Pest Plant Accord), US (California and other western states): check local rules before planting

Is Mexican feather grass toxic?

People: not known to be toxic
Cats: mildly toxic
Dogs: mildly toxic
Parts: seed awns

Not chemically toxic, but sharp awned seeds can injure the eyes, skin and mouths of dogs, cats and grazing animals.

If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.

Companion planting: what to grow with Mexican feather grass

No well-documented helpful pairing. Group it with plants that like full sun and low water.

See Mexican feather grass in a botanical garden

It grows in this sample garden, which you can walk through in 3D:

Denver Botanic Gardens (24 plants)

Questions about Mexican feather grass

How far apart should I plant Mexican feather grass?: About 40 cm (16 in) apart, centre to centre. A mature plant spreads 30–50 cm (12–20 in).
Does Mexican feather grass need full sun?: Full sun: at least 6 hours of direct sun a day.
How much water does Mexican feather grass need?: Low water. Drought tolerance is high and waterlogging tolerance none.
How cold-hardy is Mexican feather grass?: It tolerates about -17 °C (1 °F) once established, roughly USDA zone 7.
When does Mexican feather grass flower?: From about June for 9–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
Is Mexican feather grass poisonous to cats and dogs?: For cats it is mildly toxic; for dogs mildly toxic; for people not known to be toxic. Not chemically toxic, but sharp awned seeds can injure the eyes, skin and mouths of dogs, cats and grazing animals.
What grows well with Mexican feather grass?: There is no well-documented companion pairing for Mexican feather grass. Group it with plants that like the same sun (full sun) and water (low).

Sources and evidence

Evidence grade B (B: extension service or peer-reviewed).

RHS Plant Finder, Royal Horticultural Society
CABI Invasive Species Compendium, CABI
Missouri Botanical Garden Plant Finder, Missouri Botanical Garden

Notes and assumptions

Self-seeds freely; deadhead before seed set or avoid planting near bushland, rangeland or paddocks.
Short-lived, often 3 to 5 years, but replaced by seedlings.

Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.

Related plants

Fountain grass Pennisetum alopecuroides
Sweet corn Zea mays var. saccharata
Lemongrass Cymbopogon citratus
Clumping bamboo Fargesia murielae
Maiden grass (miscanthus) Miscanthus sinensis
Golden bamboo Phyllostachys aurea
Switchgrass Panicum virgatum
Little bluestem Schizachyrium scoparium