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Clematis Jackmanii

Clematis x jackmanii

The most popular and reliable clematis variety, famous for its prolific display of rich purple flowers that bloom from mid-summer through early fall. This vigorous climbing vine can transform any vertical space with its abundant 4-6 inch blooms, making it perfect for trellises, arbors, and fences. Jackmanii is incredibly hardy and forgiving, making it the ideal choice for gardeners new to clematis growing.

Harvest

N/Ad

Days to harvest

📅

Sun

Full sun to partial shade

☀️

Zones

3–9

USDA hardiness

🗺️

Difficulty

Easy to Moderate

🌱

Planting Timeline

Zone:

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Start Indoors

Transplant

Direct Sow

Start Indoors

Transplant

Direct Sow

Showing dates for Clematis Jackmanii in USDA Zone 7

All Zone 7 flower →

Zone Map

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Clematis Jackmanii · Zones 3–9

What grows well in Zone 7? →

Growing Details

Difficulty

Easy to Moderate

Spacing6-10 feet

SoilRich, well-draining, alkaline soil with good organic content

pH7.0-8.0

Water1 inch per week, consistent moisture

SeasonSummer to early fall blooming

FlavorN/A

ColorRich deep purple

Size4-6 inch diameter blooms

Zone-by-Zone Planting Calendar

Zone	Indoor Start	Transplant	Direct Sow	Harvest
Zone 3	April – May	June – July	June – August	—
Zone 4	March – April	June – June	June – July	—
Zone 5	March – April	May – June	May – July	—
Zone 6	March – April	May – June	May – July	—
Zone 7	February – March	April – May	April – June	—
Zone 8	February – March	April – May	April – June	—
Zone 9	January – February	March – April	March – May	—
Zone 10	January – January	February – March	February – April	—

Complete Growing Guide

Soil: High Organic Matter. Soil pH: Alkaline (>8.0), Neutral (6.0-8.0). Drainage: Good Drainage, Moist. Spacing: 12 inches-3 feet, 3 feet-6 feet. Growth rate: Medium. Maintenance: Medium. Propagation: Division, Layering, Stem Cutting. Regions: Coastal, Mountains, Piedmont.

Harvesting

many small, dry fruits each with a silky-plumose tail

Color: Brown/Copper. Type: Achene.

Bloom time: Fall, Spring, Summer

Storage & Preservation

Fresh-cut Clematis Jackmanii flowers last longest when stems are immediately placed in lukewarm water and then moved to cool water once conditioned. Re-cut stems underwater every 2-3 days and change water completely. Fresh arrangements typically maintain quality for 5-7 days in cool indoor conditions.

For dried preservation, harvest flowers at peak bloom before any petal deterioration. Bundle small groups of 3-5 stems with rubber bands and hang upside down in a dark, dry area with good air circulation. Properly dried clematis flowers retain color for 6-12 months when stored away from direct light.

Seed heads can be harvested after they develop their characteristic feathery plumes, usually 4-6 weeks after flowering. These make excellent additions to dried arrangements and maintain their silvery appearance indefinitely when kept dry. Both flowers and seed heads should be stored in loosely covered containers with silica gel packets to prevent moisture reabsorption.

History & Origin

Origin: N. America, Europe, India, Australia, China, Japan, New Zealand

Advantages

+Disease resistance: Black Walnut, Deer, Rabbits
+Attracts: Bees, Butterflies, Hummingbirds
+Wildlife value: Clematis leaves are food for the caterpillars of some Lepidoptera species, including the willow beauty (Peribatodes rhomboidaria). Varieties attract bees, butterflies, hummingbirds, other birds may nest in the vines.

Considerations

-Toxic (Leaves, Sap/Juice): High severity
-Causes contact dermatitis

Companion Plants

Plant Together

Hosta

Provides shade for clematis roots while allowing vine to climb above

Lavender

Repels aphids and spider mites that commonly attack clematis

Roses

Creates beautiful color combinations and both benefit from similar growing conditions

Heuchera

Low-growing groundcover that shades clematis roots and retains soil moisture

Catmint

Deters aphids and ants while providing complementary purple-blue flowers

Astilbe

Thrives in partial shade created by clematis and helps cool root zone

Clematis Montana

Different bloom times extend flowering season and similar care requirements

Boxwood

Evergreen structure provides year-round support and root shading

Keep Apart

Black Walnut

Releases juglone toxin that inhibits clematis growth and can cause wilting

Large Maples

Shallow root system competes aggressively for water and nutrients

Mint

Invasive spreading can overwhelm clematis root system and compete for resources

Nutrition Facts

Calories

15kcal(1%)

Protein

1.03g(2%)

Carbs

3.28g(1%)

Fat

0.07g(0%)

Vitamin C

28mg(31%)

Vitamin A

97mcg(11%)

Iron

0.7mg(4%)

Calcium

39mg(3%)

Potassium

173mg(4%)

Per 100g serving. % Daily Value based on 2,000 calorie diet. Source: USDA FoodData Central (FDC #169270)

Pests & Disease Resistance

Resistance

Good resistance to clematis wilt

Common Pests

Aphids, earwigs, slugs, spider mites

Diseases

Clematis wilt, powdery mildew, leaf spot

Frequently Asked Questions

How long does Clematis Jackmanii take to establish and bloom well?▼

Clematis Jackmanii typically takes 2-3 years to reach full blooming potential. First-year plants focus on root establishment and may produce only a few flowers. Second year brings more substantial growth and moderate flowering. By the third year, you'll see the spectacular abundant blooming this variety is famous for, with mature vines producing hundreds of flowers throughout the season.

When should I plant Clematis Jackmanii?▼

Plant Clematis Jackmanii in spring after the last frost date when soil has warmed to at least 50°F. In most areas, this means late April through May. Spring planting allows the vine a full growing season to establish roots before winter. Avoid fall planting in zones colder than zone 6, as newly planted clematis need time to develop cold hardiness.

Can you grow Clematis Jackmanii in containers?▼

Yes, Clematis Jackmanii grows well in large containers of at least 18-24 inches wide and deep. Use a heavy, well-draining potting mix amended with compost and lime. Container plants need more frequent watering and feeding than ground-planted vines. Provide winter protection in zones 4-6 by wrapping containers or moving them to an unheated garage during the coldest months.

Is Clematis Jackmanii good for beginners?▼

Absolutely—Clematis Jackmanii is the best clematis variety for beginners. It's exceptionally forgiving, has good disease resistance, and features simple pruning requirements. Unlike many clematis varieties that are finicky about conditions, Jackmanii adapts well to various growing situations and bounces back from mistakes. Its reliable blooming and vigorous growth provide confidence-building success for new clematis growers.

How do you prune Clematis Jackmanii?▼

Prune Clematis Jackmanii hard in late February or early March, cutting all stems back to 12-18 inches from ground level, just above a pair of strong buds. This variety blooms on new wood, so this aggressive annual pruning promotes abundant flowering and prevents the vine from becoming woody and bare at the bottom. Don't be afraid to cut it back severely—it will regrow vigorously.

What's the difference between Clematis Jackmanii and other purple clematis?▼

Clematis Jackmanii stands out for its rich, velvety purple color without any blue or red tints, plus its exceptional reliability and disease resistance. Unlike varieties such as 'The President' or 'Purple Passion,' Jackmanii blooms on new wood, making pruning simpler. It's also more vigorous and forgiving than most other purple varieties, with consistently abundant flowering from midsummer through fall.