Golden Alexanders
Zizia aurea
Punches its roots through dense clay where garden-center perennials sulk, at 1.5–2.5 ft tall — it blooms Apr through Jun.
- Full–part sun
- Average–wet
- 1.5–2.5 ft
- Blooms Apr–Jun
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- By state
- New Hampshire
- Clay soil
New Hampshire · Zones 3–6
Native Plants for Clay Soil in New Hampshire
Native plants that root happily into heavy clay — the dense, slow-draining soil that defeats so many garden-center perennials. Every species here is genuinely native to New Hampshire and the wider flora of the Northeast and hardy through zones 3–6 — proven performers for New Hampshire's cool, humid continental climate across White Mountains & northern hardwoods, not a generic list. Local standouts include Golden Alexanders and Great Blue Lobelia. 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
39 native species for New Hampshire
Each one native to your region and hardy in zones 3–6 · see this collection in other states.
Great Blue Lobelia
Lobelia siphilitica
At home in the dense clay that defeats most perennials, 2–3 ft tall — it flowers in Aug and Sep.
- Full–part sun
- Average–wet
- 2–3 ft
- Blooms Aug–Sep
Swamp Milkweed
Asclepias incarnata
Roots straight into heavy clay and even improves it, standing 3–4 ft tall; it flowers in Jul and Aug.
- Full–part sun
- Average–wet
- 3–4 ft
- Blooms Jul–Aug
Smooth Hydrangea
Hydrangea arborescens
Roots straight into heavy clay and even improves it, standing 3–5 ft tall; it blooms Jun through Aug.
- Part shade
- Average
- 3–5 ft
- Blooms Jun–Aug
Buttonbush
Cephalanthus occidentalis
At home in the dense clay that defeats most perennials, 5–10 ft tall, and it blooms Jun through Aug.
- Full–part sun
- Average–wet
- 5–10 ft
- Blooms Jun–Aug
Scarlet Beebalm
Monarda didyma
At home in the dense clay that defeats most perennials, 2.5–4 ft tall, and it flowers in Jul and Aug.
- Full–part sun
- Average–wet
- 2.5–4 ft
- Blooms Jul–Aug
Black-Eyed Susan
Rudbeckia hirta
At home in the dense clay that defeats most perennials, 1.5–3 ft tall, flowering as it blooms Jun through Sep.
- Full–part sun
- Dry–average
- 1.5–3 ft
- Blooms Jun–Sep
Trumpet Honeysuckle
Lonicera sempervirens
A clay-buster — thrives in the slow-draining ground, 8–15 ft tall, and it blooms Apr through Sep.
- Full–part sun
- Dry–average
- 8–15 ft
- Blooms Apr–Sep
Butterfly Weed
Asclepias tuberosa
Punches its roots through dense clay where garden-center perennials sulk, at 1.5–2.5 ft tall, and it blooms Jun through Aug.
- Full sun
- Dry
- 1.5–2.5 ft
- Blooms Jun–Aug
Foxglove Beardtongue
Penstemon digitalis
Punches its roots through dense clay where garden-center perennials sulk, at 2–4 ft tall; it flowers in May and Jun.
- Full–part sun
- Dry–average
- 2–4 ft
- Blooms May–Jun
Wild Bergamot
Monarda fistulosa
Roots straight into heavy clay and even improves it, standing 2–4 ft tall — it blooms Jun through Aug.
- Full–part sun
- Dry–average
- 2–4 ft
- Blooms Jun–Aug
Cardinal Flower
Lobelia cardinalis
Punches its roots through dense clay where garden-center perennials sulk, at 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
Roots straight into heavy clay and even improves it, standing 2–4 ft tall; it flowers in Jul and Aug.
- Full sun
- Average–wet
- 2–4 ft
- Blooms Jul–Aug
Serviceberry
Amelanchier canadensis
A clay-buster — thrives in the slow-draining ground, 15–25 ft tall, flowering as it flowers in Apr and May.
- Full–part sun
- Average–wet
- 15–25 ft
- Blooms Apr–May
Purple Coneflower
Echinacea purpurea
Punches its roots through dense clay where garden-center perennials sulk, at 2–4 ft tall; it blooms Jun through Sep.
- Full–part sun
- Dry–average
- 2–4 ft
- Blooms Jun–Sep
New England Aster
Symphyotrichum novae-angliae
At home in the dense clay that defeats most perennials, 3–5 ft tall, and it flowers in Sep and Oct.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Sep–Oct
Culver's Root
Veronicastrum virginicum
A clay-buster — thrives in the slow-draining ground, 3–5 ft tall, and it blooms Jun through Aug.
- Full–part sun
- Average–wet
- 3–5 ft
- Blooms Jun–Aug
Eastern Redbud
Cercis canadensis
A clay-buster — thrives in the slow-draining ground, 20–30 ft tall, and it flowers in Mar and Apr.
- Full–part sun
- Dry–average
- 20–30 ft
- Blooms Mar–Apr
Obedient Plant
Physostegia virginiana
A clay-buster — thrives in the slow-draining ground, 2–4 ft tall, flowering as it flowers in Aug and Sep.
- Full–part sun
- Average–wet
- 2–4 ft
- Blooms Aug–Sep
Short-Toothed Mountain Mint
Pycnanthemum muticum
Roots straight into heavy clay and even improves it, standing 2–3 ft tall — it blooms Jul through Sep.
- Full–part sun
- Dry–average
- 2–3 ft
- Blooms Jul–Sep
Arrowwood Viburnum
Viburnum dentatum
Punches its roots through dense clay where garden-center perennials sulk, at 6–10 ft tall; it flowers in May and Jun.
- Sun to shade
- Average–wet
- 6–10 ft
- Blooms May–Jun
Common Yarrow
Achillea millefolium
At home in the dense clay that defeats most perennials, 1.5–3 ft tall, and it blooms May through Aug.
- Full sun
- Dry–average
- 1.5–3 ft
- Blooms May–Aug
Winterberry
Ilex verticillata
A clay-buster — thrives in the slow-draining ground, 5–10 ft tall — it flowers in Jun and Jul.
- Full–part sun
- Average–wet
- 5–10 ft
- Blooms Jun–Jul
Spotted Joe-Pye Weed
Eutrochium maculatum
A clay-buster — thrives in the slow-draining ground, 4–7 ft tall; it blooms Jul through Sep.
- Full–part sun
- Average–wet
- 4–7 ft
- Blooms Jul–Sep
15 more also qualify: Spicebush, Common Boneset, Virginia Creeper, American Elderberry, Fragrant Sumac, Ninebark, Inkberry Holly, Common Milkweed, Blue Vervain, Red-Twig Dogwood, Cinnamon Fern, Switchgrass, Little Bluestem, Indian Grass, Big Bluestem.
Sourcing
Where to find these in New Hampshire
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.