Flower profile

Mallow-leaf ninebark

Physocarpus malvaceus

Mallow-leaf ninebark (Physocarpus malvaceus) is a shrub in the Rosaceae family, native in the lower 48 states, blooming mostly May–June across the U.S.

Native to Montana

Mallow-leaf ninebark is a flowering plant that USDA PLANTS lists as native in the lower 48 states. In Montana it's most often seen in bloom in June–July.

8states where USDA records it

518MT sightings*

1,594U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Montana

Quick look

Physocarpus malvaceus is a species of flowering plant in the rose family known by the common name mallow ninebark. It is native to western North America.
From Wikipedia's article Physocarpus malvaceus, CC BY-SA 4.0.

It belongs to the Rosaceae family. ^iNaturalist
USDA PLANTS describes it as a shrub with a perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as native in the lower 48 states and records it in 8 states. ^{USDA PLANTS}
NatureServe lists it as native to Montana. ^NatureServe
In Montana, most iNaturalist sightings of it in flower come in June–July. ^iNaturalist
USDA PLANTS lists its flower color as white. ^{USDA PLANTS}
USDA PLANTS gives its bloom period as late spring. ^{USDA PLANTS}
USDA PLANTS lists a mature height of about 15 ft. ^{USDA PLANTS}
iNaturalist has 518 research-grade sightings of it in Montana, ranking #89 among the 128 flowers on our Montana list. ^iNaturalist

When does it bloom?

In Montana, most flowering sightings come in June–July.

Flowering records by month in Montana (iNaturalist research-grade observations marked “Flowering”) (51 records)

Conservation status

Federal (U.S. ESA): Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. ^{USFWS ECOS}
NatureServe global: G5 Secure worldwide. ^NatureServe
Montana: No list Montana has no state law listing endangered or threatened plants, so we show NatureServe's Montana ranks instead. NatureServe: S5, secure in Montana.
Rare elsewhere: Other states where NatureServe ranks it rare or missing: NV (S1). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list.

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records mallow-leaf ninebark in 8 states.

AKMEVTNHWAIDMTNDMNILWIMINYRIMAORNVWYSDIAINOHPANJCTCAUTCONEMOKYWVVAMDDEAZNMKSARTNNCSCDCOKLAMSALGAHITXFL

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Colorado, Idaho, Montana, Nevada, Oregon, Utah, Washington, Wyoming.

Montana counties with USDA records: Beaverhead, Carbon, Fergus, Gallatin, Granite, Jefferson, Judith Basin, Lake, Lewis and Clark, Lincoln, Madison, Meagher, Mineral, Missoula, Park, Petroleum, Powell, Ravalli, Sanders, Stillwater.

Growing conditions

USDA PLANTS gives Mallow-leaf ninebark a high shade tolerance, high drought tolerance and low moisture use. It is rated for soil pH 6.0 to 7.5 and winter lows down to -33 °F.

Shade tolerance: High
Drought tolerance: High
Moisture use: Low
Soil textures it is adapted to: coarse, medium, fine
Soil pH range: 6.0 to 7.5
Minimum temperature tolerated: -33 °F
Frost-free days needed (minimum): 120
Annual precipitation range: 17 to 40 inches
Minimum root depth: 24 inches
Salinity tolerance: None
Fertility requirement: Low
Growth rate: Rapid
Lifespan: Long
Active growth period: Spring and Summer
Fruit or seed: Brown · Summer to Fall
Can be propagated by: bare root, container, seed
Commercial availability: Contracting Only

From the USDA PLANTS characteristics data for PHMA5. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

Native status by region (USDA PLANTS): Canada: Native; Lower 48 states: Native.

County records: USDA PLANTS lists it in 88 counties across 7 states; the most are in Idaho (22), Montana (20), Utah (20).

Other Physocarpus on Bloomipedia (2): Pacific ninebark, Common ninebark.

More from the Rosaceae family (103 on Bloomipedia; most observed first): Roses (genus Rosa), Multiflora rose, Mock strawberry, Black cherry, Toyon, Thimbleberry, Wineberry, Black raspberry.

More Montana flowers

Saskatoon

Amelanchier alnifolia

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🌼 Blooms in MT: May–June

Thimbleberry

Rubus parviflorus

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🌼 Blooms in MT: June–July

Chokecherry

Prunus virginiana

Native

🌼 Few flowering records in MT

Sources

USDA, NRCS. PLANTS Database, profile PHMA5.
iNaturalist, Physocarpus malvaceus: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Physocarpus malvaceus (lead quoted under CC BY-SA 4.0).
Montana: Montana noxious weed list (Admin. R. Mont. 4.5.206–4.5.210).
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Physocarpus malvaceus (global and state ranks).
Edibility and toxicity: no source found (marked "not well documented").
Photo: Hugo Innes via iNaturalist · CC BY 4.0 · resized.