Cold hardiness

Future

2050

2100

These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.

Now

Zone 6b

USDA

Published baseline for this location from 1991-2020.

Source: USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer

Well-suited

2050

Zone 7a

Plotwright

Projected zone for this same location in 2050 (2041-2070) using SSP3-7.0 (regional rivalry).

Well-suited

In plain terms: This location is in Zone 6b today. Its hardiness profile is cold winters, and coldest nights are typically around -3°F. By 2050, the projected hardiness zone is Zone 7a based on SSP3-7.0 (regional rivalry). That is a +0.5-zone shift from Zone 6b to Zone 7a by 2050.

✓

Well-suited today and still thriving in 2050.

Heat tolerance

Future

2050

2100

Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.

Loading AHS heat-zone data for this location...

Where this plant fits

Suitable across 41 ecoregions — 40 climate-resilient through 2070 · 1 suited today. Best matches first.

Appalachian mixed mesophytic forests

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Appalachian-Blue Ridge forests

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Arizona Mountains forests

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Atlantic coastal pine barrens

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Blue Mountains forests

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Canadian Aspen forests and parklands

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Central Pacific Northwest coastal forests

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Central Tallgrass prairie

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Central-Southern Cascades Forests

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Chilean Matorral

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What it needs

Conditions

Light

Full sun / Part sun / Part shade

Water

Moderate water

Spacing

36"

Habit

Deciduous twining large-flowered climbing vine

Care tips

•

Roots in shade, flowers in sun: mulch the root zone or underplant with low perennials while training the top into full sun.

•

Give it a sturdy trellis, arbor, or fence to twine up — at 7-10 feet it needs real vertical support.

•

Prune as Type 2: a light tidy in late winter or early spring before new growth, not a hard cut, to keep the summer flower wood.

Lifecycle

Planting

Plant in spring or fall in fertile, medium-moisture, well-drained soil in full sun to part shade. Keep the flowers in sun but shade the roots with mulch or low companion plantings, and provide a trellis, arbor, fence, or other structure to climb.

Transplanting

Clematis resent root disturbance; move only when necessary while dormant, lifting a generous root ball and keeping the crown at its original depth.

Early growth

Water consistently through establishment and keep the root zone cool and shaded. Tie new growth onto its support until it twines on its own.

Maturity

A mature vine reaches 7-10 feet and flowers abundantly in mid summer. As a Type 2 (late-winter / early-spring) pruner, prune lightly before new growth emerges; avoid hard cutting that removes the season's flower wood.

Propagation

Named hybrids are propagated vegetatively (stem cuttings or layering) to stay true to type; seed does not reproduce the hybrid reliably.

Pollination

Self-fertile

The large showy flowers are insect-visited — the NC State Extension Gardener Plant Toolbox lists Clematis x jackmanii as attracting bees, butterflies, and hummingbirds. As a horticultural hybrid it is grown for ornament rather than as a seed crop.

Plants don't grow alone

Nectar forage

Bird

Ruby-throated hummingbird (Archilochus colubris)

The NC State Extension Gardener Plant Toolbox lists Clematis x jackmanii as attracting hummingbirds.

Pollen forage

Bee

Common eastern bumblebee (Bombus impatiens)

The NC State Extension Gardener Plant Toolbox lists Clematis x jackmanii as attracting bees; common eastern bumble bees forage the pollen of the open showy flowers.

Pollen forage

Bee

European honeybee (Apis mellifera)

NC State lists the plant as bee-attracting; honey bees are among the generalist bees that visit clematis flowers for pollen.

For people

Toxic — do not consume

Not edible. The NC State Extension Gardener Plant Toolbox warns that Clematis causes severe pain in the mouth if eaten and minor, short-lived skin irritation on contact, and is toxic to humans, cats, dogs, and horses.

Native range

AHS heat range

1-11

Climate notes

•

Missouri Botanical Garden PlantFinder lists Clematis 'Jackmanii' for USDA zones 4 to 8, full sun to part shade, and medium water, blooming blue-purple in July at 7-10 feet tall and 3-6 feet wide.

•

The NC State Extension Gardener Plant Toolbox documents Clematis x jackmanii across USDA zones 4a-9b in moist, well-drained soil, blooming in summer; Plotwright adopts the broader 4a-9b published range.

•

Both sources note the classic clematis requirement: keep the roots cool and shaded while the top grows in sun. NC State and MBG both flag wilt/stem rot and powdery mildew as the main problems.

In the designer

Growth over time

84-120" tall · 36-72" spread

Mature 7-10 foot vine with an abundant mid-summer flower display.

Design roles: Focal point · Pollinator · Structure

Seasonal interest

Spring

Summer

Fall

Winter

Filled = the plant has seasonal interest · ▾ now = your current season

Clematis

At a glance

Related products

Why it matters

Cold hardiness

Heat tolerance

Where this plant fits

What it needs

Lifecycle

Pollination

Plants don't grow alone

For people

Native range

Climate notes

In the designer

Seasonal interest

Sources & citations