HOW TO GROW CLEMATIS PLANTS

CLEMATIS BASICS

Zones:

Most varieties are suitable for zones 4-9; with a few varieties hardy to zone 3 and others heat tolerant to zone 10.

Height/Spread:

Varieties from low-growing, trailing shrubs to climbers that can reach 30 to 50 feet.

Exposure:

Clematis need 5 to 6 hours of sun daily, but do appreciate some light shade in hotter climates. Excessive sun can cause petals to fade on larger-flowered varieties.

Bloom time:

There are early-blooming varieties (March to June), mid-season bloomers (April to June) and late bloomers (July to first frost).

Color:

Varieties available in shades of blue, pink, deep purple, red, and white.

Flower shape and size:

The flowers come in many flower forms including single, double, semi-double, star-shaped, open bell-shaped, bell-shaped, tulip shaped, and tubular. Most are 3 inches or less, but some can be up to 8 inches across.

Toxicity:

The ASPCA lists clematis as being toxic to dogs, cats and horses. It is noted, however, that it has a very bitter taste and may keep animals from ingesting large amounts.

Deer resistance:

Although listed as deer resistant; no plant is completely deer proof, as deer have been known to eat just about anything if hungry enough.

TYPES OF CLEMATIS

Varieties can be broken down into 3 groups based on when their flower buds are formed.

'Stand by Me' bush clematis.
Photo: Proven Winners.

ARE THERE ANY CLEMATIS THAT AREN'T VINES?

'Stand by Me' is an herbaceous, non-vining bush clematis that dies back to the ground at the end of the season. 'Stand by Me' blooms blue bell-shaped flowers from late spring until mid-summer and grows to 3 feet tall and wide. Grow in full sun to light shade. Benefits from staking or support from surrounding plants.

Zones 3-7.

Buy from Proven Winners.

HOW TO PLANT CLEMATIS

Unlike planting practices for most plants, clematis should be planted deeper than in their original pot. Photo by: Avalon / Alamy Stock Photo.

When to plant:

Plant in early spring just as they are going into their growth phase or later in the fall. Although nurseries may promote and sell them mid-to-late spring when in bloom, this isn't necessarily the best time to plant as there's not enough time to establish their roots before summer heat arrives.

Where to plant:

Consider the mature size of the plant and its growth habit to allow enough space, especially for the faster growers. Plant where the leaves will get sun, but the roots and base of the plant are shaded; the north side of a smaller shrub is ideal.

How to plant:

Plant clematis deeper than most plants, with the crown approximately 3 to 5 inches below the soil line. This will help encourage stems to emerge from dormant buds, making for a stronger multi-stemmed base. Water thoroughly after planting.

Planting Tips:

• A superphosphate fertilizer can be added to the bottom of the planting hole and covered with an inch of soil.
• A 3-inch layer of mulch will help keep the roots cool, but should be kept away from the base of the plant by about 5 to 6 inches.
• Be careful handling the delicate roots — nothing can save your clematis if its roots are damaged during the planting process.
• Some people have been known to experience skin irritation, so gloves should be worn when handling them.

CLEMATIS CARE

Pruning:

The key to pruning clematis correctly is knowing what type you have. If you're unsure, the best plan is to wait and see when it starts blooming, as this will dictate how and when it should be pruned. If in doubt, there are a few simple rules you can fall back on: Don’t prune before flowering, don’t remove any stems with developing buds, and never prune in the fall as this may trigger new growth that will be susceptible to winter damage.

• Group 1: Blooms on old wood. Prune lightly right after flowering to remove any dead or damaged stems. Other stems can be cut back to maintain shape and size.
• Group 2: Blooms on both old and new wood. Prune lightly in early spring before they begin to grow. Remove any dead, damaged or spindly stems to just above a pair of healthy buds. The remaining stems can also be cut back to where good buds are visible.
• Group 3: Blooms on new wood. Prune hard in late winter down to 1 to 2 feet from the soil line. Don’t worry, they’re vigorous growers and can grow up to 8 feet in a single season.

For all 3 groups, a harder pruning in the first 2 years can help encourage a more shrub-like, multi-stemmed plant.

When deadheading, 12 to 18 inches of stem can be cut back. This will help rejuvenate your vine and keep it looking nice and healthy.

Soil:

Clematis prefer slightly alkaline soil, but will tolerate a range of pH. It is more important that the soil be rich and well-amended with organic material. Clematis roots are delicate, fussy, and need a cooler environment along with moist, but well-drained, soil. Use a good layer of mulch or surround with low-growing plants to provide shade for the roots while allowing sun for the plant above ground.

Fertilizer:

They are heavy feeders. Apply a 10-10-10 fertilizer once a month during the growing season and continue until just before flowering. Fertilizing during flowering may have a negative effect and bring blooming to a halt prematurely.

Watering:

Under normal conditions, they need about an inch of water weekly once established. In warmer climates or during extreme heat, water deeply and more frequently; this will also help to keep the roots cool.

Support:

Clematis attach themselves to host plants or structures with their leaf stalks but need help to climb vertically. Secure stems to a support or trellis to encourage upward growth.

Diseases and Pests:

Scale, whiteflies, earwigs and aphids can be a problem. Common diseases are clematis wilt, powdery mildew, rust, fungal spots and stem cankers.

CLEMATIS VARIETIES

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Photo by: Proven Winners.

Happy Jack® Purple — Buy from Proven Winners
Group 2

Zones: 5-9

Height/Spread: 6 to 8 feet tall, 3 to 4 feet wide

Exposure: Full sun to part shade

Bloom Time: Mid-summer to fall

Color: Deep purple flowers

An easy-to-grow version of the popular Clematis 'Jackmanii' with 3- to 5-inch deep purple flowers.

Photo by: Proven Winners.

'Sweet Summer Love' — Buy from Proven Winners
Group 3

Zones: 4-9

Height/Spread: 10 to 15 feet tall, 6 to 10 feet wide

Exposure: Full sun to part shade

Bloom Time: Spring & summer

Color: Cranberry-purple flowers

Fragrant flowers bloom from late spring through summer. Establishes itself in the first year and explodes with growth the second.

Photo by: Proven Winners.

'Diamond Ball' — Buy from Proven Winners
Group 2

Zones: 4-9

Height/Spread: 6 feet tall, 3 feet wide

Exposure: Full sun to part shade

Bloom Time: June through August

Color: White-blue flowers

Unique ice-blue flowers bloom early to midsummer. Easy to care for, vigorous, and disease resistant.

Photo by: Proven Winners.

Jolly Good™ — Buy from Proven Winners
Group 3

Zones: 4-9

Height/Spread: 7 feet tall, 3 feet wide

Exposure: Full sun to part shade

Bloom Time: Summer

Color: Light purple flowers

Light purple flowers with magenta tones bloom all summer. A vigorous grower, yet remains compact — perfect for trellises.

Photo by: Proven Winners.

Sparky™ Purple— Buy from Proven Winners
Group 1

Zones: 3-8

Height/Spread: 6 to 8 feet tall and wide

Exposure: Partial sun to full sun

Bloom Time: Mid spring to early summer

Color: Violet purple flowers (also available in pink & blue)

Unique flower shape, early bloomer, needs no pruning

Photo by: Garden World Images Ltd / Alamy Stock Photo.

C. armandii ‘Apple Blossom’
Group 1

Zones: 7-9

Height/Spread: Vines can reach 20 to 25 feet long

Exposure: Partial shade to full sun

Bloom Time: Early to mid-spring

Color: Pale pink to white flowers, deeper pink buds

Evergreen foliage, vanilla scented flowers, quick grower

Photo by: Garden World Images Ltd / Alamy Stock Photo.

Clematis ‘Cezanne’
Group 2

Zones: 4-9

Height/Spread: 3 to 4 feet tall and 1 to 2 feet wide

Exposure: Partial shade to full sun

Bloom Time: Spring

Color: Blue flowers

Compact, excellent choice for small spaces or containers

Photo by: High Mountain / Shutterstock.

Clematis terniflora (syn. C. paniculata)
Group 3

Zones: 5-9

Height/Spread: 15 to 30 feet tall and wide

Exposure: Partial shade to full sun

Bloom Time: Late summer to fall

Color: Creamy white flowers

Commonly called sweet autumn clematis; prone to self-seeding and spreading

Photo by: John Richmond / Alamy Stock Photo.

Clematis ‘Nelly Moser’
Group 2

Zones: 4-8

Height/Spread: 6 to 10 feet tall and wide

Exposure: Partial shade to full sun

Bloom Time: Spring

Color: Pale pink flowers with darker pink striped petals

Larger flowers, 6-8 inches across

Photo by: Age Fotostock / Alamy Stock Photo.

Clematis virginiana
Group 3

Zones: 3-8

Height/Spread: 12 to 20 feet tall and 3 to 6 feet wide

Exposure: Partial shade to full sun, although very shade tolerant

Bloom Time: Late summer to fall

Color: White flowers

Can spread aggressively by self-seeding and suckering, native to eastern North America

Photo by: Anne Gilbert / Alamy Stock Photo.

Clematis florida ‘Sieboldii’
Group 2

Zones: 6-9

Height/Spread: 6 to 8 feet tall and 3 to 6 feet wide

Exposure: Partial shade to full sun

Bloom Time: Spring to fall

Color: White with purple center flowers

Elegant bi-colored clematis, well-suited for large containers

LANDSCAPE DESIGN IDEAS

With so many varieties of clematis, the design possibilities are nearly endless.

• Plant a combination of varieties from each group for blooms from spring until frost.
• Use larger, more vigorous climbers for a quick cover of trellises, arbors, pergolas, or fences.
• Varieties, like ‘Cezanne’, ‘Crystal Fountain’ or Rosemoor are well-suited for containers, tucked in corners or smaller spaces.
• Herbaceous varieties such as C. heracleifolia, make excellent ground cover if left to sprawl.
• Add square footage to a smaller garden with clematis by making use of vertical space.
• Peonies, Asiatic lilies and Knock Out roses are good garden companions.

CUTTING & ARRANGING CLEMATIS

Whether used solo or in a bunch with other spring or summer blooms, clematis make outstanding cut flowers. They can last up to 2 weeks from bud to fully open, with double-flowered varieties often lasting longer than singles. Here are some tips to make the most of your cut clematis:

• Cut clematis flowers in the morning.
• Choose younger blooms that are no more than three-fourths open, and even less is better.
• Cut early-to-mid-spring bloomers at the bottom of the flower stalk, not into the main stem.
• Cut large-flowered varieties anywhere from 6 to 24 inches down the stem.
• Drape a length of stem from a vase to make use of the vine’s flexibility.
• Cut flowers an inch below their base and float in a bowl.
• Combine with hydrangea, peonies and roses to create a cottage-style arrangement (use this combination in the garden as well!)
• Keep vases of cut flowers in a cool location and out of direct sunlight to help lengthen their lifespan.