Ornamental · Poaceae

Pink Muhly Grass

Muhlenbergia capillaris

Hand it full sun and lean, dry ground, and pink muhly grass puts on a rose-pink haze every single fall.

Light

Full sun

Water

Every 7–⁠14 days

Hardiness

USDA 6–⁠10

Mature size

2–⁠3 ft · 0.6–⁠0.9 m

Pet-safe
Pink Muhly Grass

Overview

Pink muhly grass is a clump-forming native from the eastern and southern United States, and it's grown for one showstopping trick. Most of the year it just sits there as a fountain of fine green blades, but then fall shows up and it sends up an airy cloud of rose-pink plumes that catches the low light and pretty much glows. It's a member of the grass family, and honestly, it asks for next to nothing.

So what makes it so easy? It just doesn't want much. Once its roots are down it takes heat, salt, and long dry spells in stride, and it skips the pests and diseases that plague pickier ornamentals. The one thing it's picky about is where it lives, and that means full sun and lean, fast-draining soil. Rich, wet ground is where it all goes soft and floppy.

Plant a bunch of it together and the fall show reads clear across the yard, a wide drift of pink that hangs on for weeks before mellowing to tan for winter. It stays put instead of running around, so it won't hijack your bed, and one cut-back in late winter is basically the whole season's to-do list.

Care

The short version: full sun, lean and well-drained soil, and barely any water once it's settled in. Skip the fertilizer, let it stand through winter, and cut it back hard in late winter before the new growth wakes up.

Light

Give it full sun, 6 or more hours a day. That sun is what builds the dense, upright clump and the heavy pink bloom, and it's easily the biggest thing that decides how good the plant looks. Stick it in shade and the stems go weak, the plumes thin out, and the whole clump splays open.

Water

Water it regularly through the first season so the roots settle in, and after that it barely needs you. Grown-up plants are seriously drought tolerant and get by on rainfall in most spots. The real risk runs the other way, though, since wet, soggy ground rots the crown.

Soil

It likes lean, dry, well-drained soil, that sandy or rocky kind of ground where fussier plants throw a fit. Any pH from 5.5 to 8.0 works, and it'll even take clay as long as the drainage is sharp. Skip the rich, amended beds, since those just leave it floppy.

Temperature

This is a hardy, roll-with-it grass that's comfortable across a big swing, roughly -9°F to 104°F (-23°C to 40°C). It takes summer heat without blinking and comes through hard winters down to zone 6.

Humidity

Regular outdoor humidity is plenty, and there's no number to chase here. What matters way more is good drainage and air around the crown, because if there's one thing it can't stand, it's staying wet.

Feeding

Don't feed it, plain and simple. This native actually does best in lean, low-fertility soil, and fertilizer backfires by pushing soft, leafy growth and fewer blooms. Keeping it lean is what keeps it upright and flowering.

Pruning

There's just the one job all year. Cut the whole clump back to about 6 to 8 inches (15 to 20 cm) in late winter or early spring, before the new blades come up. Leave the old foliage standing over winter for a bit of cold protection and some good looks.

Repotting

It hardly ever needs dividing or a new pot. After a lot of years an old clump might die out in the center, leaving a bare ring with less vigor and fewer plumes, and that's your cue to lift and split it instead of repotting.

Size & spacing

Plants get to about 2 to 3 feet (61 to 91 cm) tall and just as wide. Space them roughly that far apart, around 2 to 3 feet (61 to 91 cm), so each clump can round out into its full shape with a little breathing room.

When to plant

Pink muhly grass runs on a warm-season clock, so it greens up in spring and saves the fireworks for fall. Sow seed indoors in late winter to early spring and set plants out after the last frost, and those pink plumes roll in from September into November.

Northern hemisphere

Sow Feb–Mar
Plant Apr–May
Bloom Sep–Nov

Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.

  • Sow: Late winter to early spring
  • Plant: Spring after last frost
  • Harvest: September to November

Hardiness

USDA hardiness zones: 6–10

Temperature: down to -23°C

Troubleshooting

This grass is tough, so trouble's pretty rare, and when it happens it's almost always the spot, not a disease. The clues turn up in the bloom, the crown, or the base of the stems. Find what matches below, then just fix the conditions behind it.

Severe

The plant rots or fades in soggy ground

If the crown's gone mushy and the clump is thinning from the middle, that's root and crown rot, and wet, heavy soil is the culprit. It just can't sit in ground that stays soggy. So get it into sharp-draining sandy or rocky soil, mound it up a bit if you're stuck with clay, and let things dry out between waterings.

Fix:

  • Plant in well-drained sandy or rocky soil, or amend heavy soil and plant on a raised mound or berm
  • Reduce irrigation; allow soil to dry between waterings
  • Remove dead rotted portions and replant healthy divisions in a drier, well-drained site
Setback

White cottony clusters at the base of a stressed plant

See waxy white fluff tucked at the leaf bases and crown? That's muhly grass mealybug, pretty much the only pest that ever bothers this tough grass. Pile on enough of them and the plant turns stunted and off-color. Just cut back and toss the infested foliage in late winter, lay off the fertilizer that feeds the soft growth they love, and let the good bugs handle the rest.

Fix:

  • Cut back and remove heavily infested foliage in late winter
  • Encourage natural predators and avoid excess fertilizer that flushes soft growth
Cosmetic

Few or no pink plumes, and the clump flops open

No fall color, or a clump that's leaning apart? Nine times out of ten it's shade or ground that's too rich. Shade leaves the stems soft and holds the flowers back, and rich, often-watered soil grows loads of leaf but hardly any plumes while letting the whole thing sprawl. Give it a spot with 6 hours of sun, quit feeding it, and cut back on water so it grows lean and stands up straight.

Fix:

  • Relocate or plant in full sun (6 or more hours of direct sun) for the best plume color, density, and upright form
  • Stop fertilizing and reduce watering; grow in lean, dry, well-drained soil
  • Cut back in late winter so vigorous new growth emerges in the right conditions

Toxicity

Good news if you've got pets: pink muhly grass is safe all the way around. There's nothing toxic in it for cats, dogs, horses, rabbits, livestock, or people, and it's not on the ASPCA's list of harmful plants. The only thing worth a mention? That heavy fall pollen, which can bug allergy-prone folks.

Safe for

People · Cats · Dogs · Horses · Rabbits · Livestock · Birds

Cats None

Cats are fine around it, since there's nothing toxic in the leaves or plumes. If one grazes a big mouthful it might bring it back up, the way grass tends to, and that's really all there is to it.

Dogs None

Dogs have nothing to fear here either. Got a chewer? The worst you'll probably see is a little vomiting, the same thing any grass can cause.

Horses None

Horses can graze right next to it, no worries, because there aren't any toxins in it.

Rabbits None

Rabbits can nibble away at the foliage safely, since it's just a plain, harmless grass.

Livestock None

Cattle, goats, and sheep can all graze this native grass freely, and none of them are at any risk.

Birds None

Birds do just fine around it, and plenty of them pick at the seed heads all through fall and winter.

People None

It's safe to handle and plant with your bare hands. The one thing worth flagging is that heavy fall pollen, which can set off seasonal allergies if you're the sensitive type.

Not poisonous, but pets that nibble large amounts of grass may vomit, and the abundant fall pollen can aggravate seasonal allergies in sensitive people.

Varieties

Most people just grow the plain species for its pink fall haze, and that's great, but a handful of selections and close relatives are worth a look.

White Cloud

This one trades the usual pink for white to cream plumes, and it handles tar spot better than the plain species does.

Pink Flamingos

It's a taller natural hybrid of M. capillaris and M. lindheimeri that gets to 3 to 4 feet, with bright pink plumes that turn silvery-gray as they age.

Lindheimer's muhly (Muhlenbergia lindheimeri)

This is a bigger cousin from central Texas, a 2 to 5 foot silvery-plumed clumping bunchgrass that folks often use as a tall specimen.

Bamboo muhly (Muhlenbergia dumosa)

It's a relative with arching, semi-woody bamboo-like stems and lacy pale-green foliage, and it fountains out to 5 feet tall and wide.

How to propagate

Pink muhly grass is a cinch to multiply, whether you split a clump you've already got or start fresh from seed.

DivisionEasy

Spring · One growing season

Want more of it? The easiest route is to divide an established clump in early spring. Lift the whole crown out, split it into chunks, and pop them back in the ground. Each piece takes a single growing season to settle in, then it's back as a full plant.

SeedEasy

Spring (sow indoors late winter to early spring)

Seed's an easy option too, and you don't have to worry about it running wild, because this grass grows in a clump instead of spreading by rhizomes. Sow it indoors in late winter to early spring, then move the seedlings outside once frost's done. Give them one to two growing seasons and they'll hit blooming size.

Myths

Myth

Muhly grass needs rich, fertilized, frequently watered soil to bloom well.

Reality

Nope, it's the exact opposite. Keep it in full sun and lean, dry, well-drained soil and it blooms its best and stands up tall, but hand it rich, wet, fed ground and you'll get floppy leaves, hardly any plumes, and a good chance of root rot. Give it the hard life and it flowers beautifully.

Sources