Swamp Milkweed
Asclepias incarnata
Happy in the wet center of a rain garden and ground that stays soggy after a storm, rose pink flowers, where it flowers in Jul and Aug.
- Full–part sun
- Average–wet
- 3–4 ft
- Blooms Jul–Aug
Montana · Zones 3–5
Native Rain Garden Plants in Montana
Moisture-loving natives for rain gardens, pond edges, downspout basins, and the low spots that stay soggy after a storm. Montana sits in a landscape of Northern Rockies & Great Plains steppe, and the natives that thrive here are the ones built for its cold, semi-arid character. The list below — led by Swamp Milkweed and Serviceberry — is filtered to species genuinely native to Montana and the wider flora of the Mountain West and hardy through zones 3–5. A rain garden catches roof and driveway runoff and lets it soak in instead of rushing to the storm drain, and these natives are built for that boom-and-bust of flood then dry. Put the most water-tolerant species in the wet center and the merely moisture-loving ones up on the sloped edges. Once established they handle both the standing water and the dry weeks between storms.
The plants
19 native species for Montana
Each one native to your region and hardy in zones 3–5 · see this collection in other states.
Serviceberry
Amelanchier canadensis
Built for the wet center of a rain garden and the boom-and-bust of storm runoff, reaching 15–25 ft, where it flowers in Apr and May.
- Full–part sun
- Average–wet
- 15–25 ft
- Blooms Apr–May
Golden Alexanders
Zizia aurea
Built for the wet center of a rain garden and the boom-and-bust of storm runoff, reaching 1.5–2.5 ft, where it blooms Apr through Jun.
- Full–part sun
- Average–wet
- 1.5–2.5 ft
- Blooms Apr–Jun
Spotted Joe-Pye Weed
Eutrochium maculatum
For the wet center of a rain garden and damp low spots, 2–4 ft wide, where it blooms Jul through Sep.
- Full–part sun
- Average–wet
- 4–7 ft
- Blooms Jul–Sep
Culver's Root
Veronicastrum virginicum
Built for the wet center of a rain garden and the boom-and-bust of storm runoff, 1.5–2 ft wide, where it blooms Jun through Aug.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Jun–Aug
Great Blue Lobelia
Lobelia siphilitica
For the wet center of a rain garden and damp low spots, deep blue flowers, where it flowers in Aug and Sep.
- Full–part sun
- Average–wet
- 2–3 ft
- Blooms Aug–Sep
Buttonbush
Cephalanthus occidentalis
Built for the wet center of a rain garden and the boom-and-bust of storm runoff, hardy in zones 5–9, where it blooms Jun through Aug.
- Full–part sun
- Average–wet
- 5–10 ft
- Blooms Jun–Aug
Cup Plant
Silphium perfoliatum
Built for the wet center of a rain garden and the boom-and-bust of storm runoff, 2–4 ft wide, where it blooms Jul through Sep.
- Full–part sun
- Average–wet
- 5–8 ft
- Blooms Jul–Sep
Douglas Aster
Symphyotrichum subspicatum
Takes the wet center of a rain garden through flood and dry spell alike, happy in clay and loam soil, where it blooms Aug through Oct.
- Full–part sun
- Average–wet
- 2–4 ft
- Blooms Aug–Oct
Dense Blazing Star
Liatris spicata
Takes the wet center of a rain garden through flood and dry spell alike, spreading 12–18 in, where it flowers in Jul and Aug.
- Full sun
- Average–wet
- 2–4 ft
- Blooms Jul–Aug
New England Aster
Symphyotrichum novae-angliae
Happy in the wet center of a rain garden and ground that stays soggy after a storm, 3–5 ft tall, where it flowers in Sep and Oct.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Sep–Oct
Obedient Plant
Physostegia virginiana
For the wet center of a rain garden and damp low spots, for clay and loam ground, where it flowers in Aug and Sep.
- Full–part sun
- Average–wet
- 2–4 ft
- Blooms Aug–Sep
Common Boneset
Eupatorium perfoliatum
Happy in the wet center of a rain garden and ground that stays soggy after a storm, spreading 2–3 ft, where it flowers in Aug and Sep.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Aug–Sep
Ninebark
Physocarpus opulifolius
Built for the wet center of a rain garden and the boom-and-bust of storm runoff, reaching 5–10 ft, where it flowers in May and Jun.
- Full–part sun
- Dry to wet
- 5–10 ft
- Blooms May–Jun
Red-Twig Dogwood
Cornus sericea
Built for the wet center of a rain garden and the boom-and-bust of storm runoff, happy in clay and loam soil, where it flowers in May and Jun.
- Full–part sun
- Average–wet
- 6–9 ft
- Blooms May–Jun
American Elderberry
Sambucus canadensis
Happy in the wet center of a rain garden and ground that stays soggy after a storm, spreading 6–12 ft, where it flowers in Jun and Jul.
- Full–part sun
- Average–wet
- 6–12 ft
- Blooms Jun–Jul
Blue Vervain
Verbena hastata
For the wet center of a rain garden and damp low spots, 3–5 ft tall, where it blooms Jul through Sep.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Jul–Sep
Big Bluestem
Andropogon gerardii
Takes the wet center of a rain garden through flood and dry spell alike, happy in sand, clay, and loam soil.
- Full sun
- Dry to wet
- 4–7 ft
- Fall color
Switchgrass
Panicum virgatum
Takes the wet center of a rain garden through flood and dry spell alike, reaching 3–6 ft.
- Full–part sun
- Dry to wet
- 3–6 ft
- Fall color
Sourcing
Where to find these in Montana
Seeds & live plants on Amazon
Seed packets, plugs, and starter plants for many of these species ship to your door.
Browse on AmazonSome links here are affiliate links — we may earn a small commission at no extra cost to you. The surest source of locally-adapted stock is a native-plant nursery or a native plant society sale in your area.