Great Blue Lobelia
Lobelia siphilitica
A clay-buster — thrives in the slow-draining ground, 2–3 ft tall, flowering as it flowers in Aug and Sep.
- Full–part sun
- Average–wet
- 2–3 ft
- Blooms Aug–Sep
Wisconsin · Zones 3–5
Native Plants for Clay Soil in Wisconsin
Native plants that root happily into heavy clay — the dense, slow-draining soil that defeats so many garden-center perennials. For Wisconsin, the right natives are shaped by Northern forest, driftless prairie & oak savanna and a cold continental climate. Every species below, from Great Blue Lobelia and Golden Alexanders to the rest of the list, is genuinely native to Wisconsin and the wider flora of the Midwest and hardy through zones 3–5. Heavy clay is actually fertile and moisture-holding; the trick is choosing plants whose deep, muscular roots can punch through it and even improve it over time. Avoid working clay when it is wet, plant a little high to keep crowns from sitting in water, and mulch to keep the surface from baking into a crust. These natives do the soil-building for you.
The plants
46 native species for Wisconsin
Each one native to your region and hardy in zones 3–5 · see this collection in other states.
Golden Alexanders
Zizia aurea
Punches its roots through dense clay where garden-center perennials sulk, at 1.5–2.5 ft tall, and it blooms Apr through Jun.
- Full–part sun
- Average–wet
- 1.5–2.5 ft
- Blooms Apr–Jun
Cardinal Flower
Lobelia cardinalis
At home in the dense clay that defeats most perennials, 2–4 ft tall; it blooms Jul through Sep.
- Full–part sun
- Average–wet
- 2–4 ft
- Blooms Jul–Sep
Dense Blazing Star
Liatris spicata
Punches its roots through dense clay where garden-center perennials sulk, at 2–4 ft tall; it flowers in Jul and Aug.
- Full sun
- Average–wet
- 2–4 ft
- Blooms Jul–Aug
Cup Plant
Silphium perfoliatum
At home in the dense clay that defeats most perennials, 5–8 ft tall — it blooms Jul through Sep.
- Full–part sun
- Average–wet
- 5–8 ft
- Blooms Jul–Sep
Scarlet Beebalm
Monarda didyma
Roots straight into heavy clay and even improves it, standing 2.5–4 ft tall, and it flowers in Jul and Aug.
- Full–part sun
- Average–wet
- 2.5–4 ft
- Blooms Jul–Aug
Trumpet Honeysuckle
Lonicera sempervirens
At home in the dense clay that defeats most perennials, 8–15 ft tall — it blooms Apr through Sep.
- Full–part sun
- Dry–average
- 8–15 ft
- Blooms Apr–Sep
Maximilian Sunflower
Helianthus maximiliani
At home in the dense clay that defeats most perennials, 5–8 ft tall; it blooms Aug through Oct.
- Full sun
- Dry–average
- 5–8 ft
- Blooms Aug–Oct
Aromatic Aster
Symphyotrichum oblongifolium
Punches its roots through dense clay where garden-center perennials sulk, at 1.5–2.5 ft tall, flowering as it blooms Sep through Nov.
- Full sun
- Dry
- 1.5–2.5 ft
- Blooms Sep–Nov
Foxglove Beardtongue
Penstemon digitalis
At home in the dense clay that defeats most perennials, 2–4 ft tall; it flowers in May and Jun.
- Full–part sun
- Dry–average
- 2–4 ft
- Blooms May–Jun
Smooth Hydrangea
Hydrangea arborescens
Roots straight into heavy clay and even improves it, standing 3–5 ft tall, and it blooms Jun through Aug.
- Part shade
- Average
- 3–5 ft
- Blooms Jun–Aug
Culver's Root
Veronicastrum virginicum
Roots straight into heavy clay and even improves it, standing 3–5 ft tall, and it blooms Jun through Aug.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Jun–Aug
Arrowwood Viburnum
Viburnum dentatum
Punches its roots through dense clay where garden-center perennials sulk, at 6–10 ft tall, flowering as it flowers in May and Jun.
- Sun to shade
- Average–wet
- 6–10 ft
- Blooms May–Jun
Obedient Plant
Physostegia virginiana
At home in the dense clay that defeats most perennials, 2–4 ft tall, and it flowers in Aug and Sep.
- Full–part sun
- Average–wet
- 2–4 ft
- Blooms Aug–Sep
Wild Bergamot
Monarda fistulosa
Roots straight into heavy clay and even improves it, standing 2–4 ft tall, flowering as it blooms Jun through Aug.
- Full–part sun
- Dry–average
- 2–4 ft
- Blooms Jun–Aug
Butterfly Weed
Asclepias tuberosa
A clay-buster — thrives in the slow-draining ground, 1.5–2.5 ft tall — it blooms Jun through Aug.
- Full sun
- Dry
- 1.5–2.5 ft
- Blooms Jun–Aug
Common Yarrow
Achillea millefolium
At home in the dense clay that defeats most perennials, 1.5–3 ft tall — it blooms May through Aug.
- Full sun
- Dry–average
- 1.5–3 ft
- Blooms May–Aug
Eastern Redbud
Cercis canadensis
A clay-buster — thrives in the slow-draining ground, 20–30 ft tall; it flowers in Mar and Apr.
- Full–part sun
- Dry–average
- 20–30 ft
- Blooms Mar–Apr
New England Aster
Symphyotrichum novae-angliae
Punches its roots through dense clay where garden-center perennials sulk, at 3–5 ft tall, and it flowers in Sep and Oct.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Sep–Oct
Black-Eyed Susan
Rudbeckia hirta
Punches its roots through dense clay where garden-center perennials sulk, at 1.5–3 ft tall, flowering as it blooms Jun through Sep.
- Full–part sun
- Dry–average
- 1.5–3 ft
- Blooms Jun–Sep
Winterberry
Ilex verticillata
Roots straight into heavy clay and even improves it, standing 5–10 ft tall, flowering as it flowers in Jun and Jul.
- Full–part sun
- Average–wet
- 5–10 ft
- Blooms Jun–Jul
Swamp Milkweed
Asclepias incarnata
At home in the dense clay that defeats most perennials, 3–4 ft tall — it flowers in Jul and Aug.
- Full–part sun
- Average–wet
- 3–4 ft
- Blooms Jul–Aug
Short-Toothed Mountain Mint
Pycnanthemum muticum
Roots straight into heavy clay and even improves it, standing 2–3 ft tall, and it blooms Jul through Sep.
- Full–part sun
- Dry–average
- 2–3 ft
- Blooms Jul–Sep
Buttonbush
Cephalanthus occidentalis
Roots straight into heavy clay and even improves it, standing 5–10 ft tall, and it blooms Jun through Aug.
- Full–part sun
- Average–wet
- 5–10 ft
- Blooms Jun–Aug
22 more also qualify: Prairie Blazing Star, Spotted Joe-Pye Weed, Serviceberry, Purple Coneflower, Spicebush, Blue Vervain, Virginia Creeper, Compass Plant, Common Milkweed, Sideoats Grama, Common Boneset, Rattlesnake Master, American Elderberry, Stiff Goldenrod, Fragrant Sumac, Red-Twig Dogwood, Ninebark, Cinnamon Fern, Little Bluestem, Indian Grass, Switchgrass, Big Bluestem.
Sourcing
Where to find these in Wisconsin
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.