Clematis, belonging to the Ranunculaceae or buttercup family, is an alluring plant native to North America and other parts of the world. Known for their distinctive bell-shaped flowers, clematis vines are a spectacular sight in gardens, especially when they flower from late spring to early summer.
No matter the variety, be it lavender-hued Niobe or the pristine white flowers of specific perennial clematis types, these plants adorn arbors, trellises, pergolas, and fences with arresting charm.
The diversity among the more than two hundred clematis varieties allows gardeners the possibility to select species according to their bloom time, be it early spring, midsummer, or late summer into early fall. This makes the clematis a versatile component in garden design, offering vibrant color in the landscape for much of the year.
The care of clematis plants may require a little more attention, but the reward outweighs the work significantly. Early in the first growing season, the vines are pruned to stimulate strong, new growth on either new wood or old wood, depending on the variety.
All clematis appreciate being well-fed, and a layer of compost followed by an application of a balanced fertilizer in late winter will prepare them for an abundant display.
Clematis flowers not only look stunning but also attract lovely pollinators such as butterflies and hummingbirds. The shrub’s green leaf supports the large blooms, which take on a silken sheen as they unfurl in the warmth of April sun.
As a master gardener, I love caring for these flowers and sharing what I know with others. In this guide, I’ll go over everything you need to know about clematis, including how to grow and care for it.
Botanical Name: Clematis spp.
Common Name: Clematis, Leather flower
Plant Type: Perennial, shrub, vine
Hardiness Zones: 4 – 9 (USDA)
Sun Exposure: Full
Soil Type: Loamy, well-drained
Soil pH: Neutral
Bloom Time: Winter, spring, summer, fall
Flower Color: Blue, purple, red, pink, green, yellow, white, bi-color
Native Area: North America
Clematis Plant Care
Clematis vines, natives to North America and members of the Ranunculaceae or buttercup family, are versatile perennials that thrive in USDA zones 4 through 9, enjoying both full sun and partial shade.
Plant clematis in early spring, allowing the plant to adjust before the summer heat. Use compost and fertilizer to encourage new growth on the stems, and mulch to retain moisture.
Clematis varieties range from shrub-like clematis flowers like lavender niobe, bell-shaped flowers, to large white flowers. Train the vines to climb a trellis, arbor, pergola, or fence using twines.
Prune old wood after bloom time in late winter or early spring, and new wood in early summer or midsummer, to promote healthy first growing season.
And, don’t forget the bonus, these late spring to late summer bloomers are great attractants for butterflies and hummingbirds!
Clematis are generally adoring of sunlight and thus, a good portion of them prefer growing in areas receiving full sun. However, clematis varieties are diverse, and some types would thrive better in partial shade, particularly those with paler or white flowers.
The leaves and stems should ideally receive at least six hours of sun exposure per day for the clematis vines to bloom most vibrantly. But having said that, the plant’s roots and base enjoy being kept cool.
A lightly shaded place for them or a thick layer of mulch or compost can work effectively to achieve this requirement. A balance between sun exposure and cool roots can result in an impressive bloom time, from late spring through early fall.
The proper soil conditions are crucial when preparing to plant clematis. They thrive most in a well-draining, neutral to slightly alkalitic, loose soil rich in organic matter.
Before introducing clematis plants to the garden, enrich your soil using organic compost or a well-rotted manure. Mulch is extremely beneficial to help the soil retain moisture and maintain a cooler root zone for the plant.
Plus its application around the plant base can deter pests and help keep the nutrient content of the soil high.
It’s worth noting that although clematis favors fertile and consistently moist soil, waterlogging should be avoided, as root rot can occur in such conditions.
Consistent watering is crucial for clematis vines during their first growing season. In fact, these perennials often require a deep watering at least once a week, especially during dry periods.
The soil should be kept moderately moist but never waterlogged, as their roots are prone to rot. Excessive moisture can lead to fungal diseases which can damage the plant’s stems and leaves.
From the second year onward, they are generally more drought tolerant but still appreciate regular watering, particularly during hot weather. Mulch plays a key role in conserving soil moisture, so it is highly recommended.
Temperature and Humidity
Clematis vines flourish in USDA zones 4 through 9, with temperatures ranging from -30 degrees Fahrenheit to 50 degrees Fahrenheit, depending on the variety.
As they have adapted to a wide range of humidity conditions, clematis can successfully grow in both dry and humid climates.
Clematis vines are hungry plants and need a steady supply of nutrients to produce their signature large, vibrant blooms. Fertilizers rich in organic matter provide the perfect boost these perennials need to thrive.
After you initially plant clematis, work a handful of well-rotted compost into the soil and then top with a layer of mulch to keep the roots cool and moist.
In the early spring, just as new growth begins to emerge, apply a balanced fertilizer to fuel the plant’s vigor throughout the blooming season.
Then, starting in midsummer, switch to a high potassium fertilizer to aid in bud and flower formation for the following year. Be sure not to overfeed your clematis, as too much fertilizer may lead to an abundance of leaf growth and fewer clematis flowers.
Pruning is an important part of clematis care that greatly influences their growth and bloom. Clematis varieties that flower on new wood should be pruned in late winter or early spring, cutting back the stems to 1-2 feet off the ground to encourage new growth and abundant blooms in late summer.
Those that bloom on old wood should be lightly pruned in early summer, just after the blooms fade, to tidy up the plant and remove faded flowers. In contrast, those flowering late in the season or in early fall flower on the current year’s growth and only need light pruning in late winter to remove dead or weak stems.
Remember to use clean, sharp tools when pruning to avoid damaging the plant. Meanwhile, during the first growing season, prune clematis lightly to encourage branching and create a fuller plant.
Types of Clematis
‘Niobe’ Clematis: Recognized as one of several stunning clematis varieties, the ‘Niobe’ Clematis is a striking long-flowering perennial that flutters like a velvet heart in full sun to partial shade. Its deep ruby blooms emerge from May to early fall, attracting both butterflies and hummingbirds.
‘Sweet Autumn’ Clematis: As a member of the Ranunculaceae or buttercup family, Sweet Autumn Clematis reflects its heritage through its profuse, white flowers that mirror the shape of a buttercup. This vigorous climber blooms profusely in late summer, producing a mesmerising vanilla scent.
‘Blue Ravine’ Clematis: When you plant clematis of the ‘Blue Ravine’ variety, expect a spectacular display of lavender-blue flowers from late spring to midsummer.
‘Josephine’ Clematis: Josephine Clematis is a beloved breed for its distinctive bell-shaped flowers that bloom from early summer to early fall, drawing the eye with a thick pile of double pink blooms.
‘Alba Luxurians’ Clematis: The ‘Alba Luxurians’ Clematis is an appealing perennial that produces plentiful white flowers in late summer. Growing best in full sun or partial shade, its vivid green leaf and stems provide a mesmerising backdrop for the clusters of white flowers.
How to Plant Clematis From Seed
The first step in propagating a Clematis vine is getting the seeds. Clematis seeds are usually collected in late summer or early fall. Once you have the seeds, they should be sown in a cold frame or directly into the compost.
A cold frame is a transparent-roofed enclosure, built low to the ground that protects plants from adverse weather conditions. The compost should be deep enough to accommodate the developing roots. This depth is crucial during the first growing season of clematis vines.
Sow the seeds thinly to avoid overcrowding of the emerging seedlings. Cover the seeds lightly with some additional compost. The compost should be rich enough to support new growth until the seedlings are ready to be pruned and transplanted. The budding clematis plants are then left to grow.
Once the seedlings have developed, they can be moved to their final location. Clematis vines thrive best in full sun to partial shade. Although they appreciate having their leafy stems in the sun, their roots are in a preference for cool conditions. Mulch can be used to keep the soil cool.
The ideal place to plant clematis is near a fence, trellis, arbor, or pergola. These structures will support the climbing vines as they grow and showcase the striking clematis flowers when they bloom.
How to Propagate Clematis
Step 1: Choosing the Right Variety and Location
Not all clematis varieties are created equal. Native to various regions stretching from North America to Asia, there are an estimated 250 to 325 species of clematis.
When choosing one, consider the bloom time with options ranging from early spring to late summer. Also ensure the selected spot provides enough sunlight – clematis vines generally prefer full sun but can also tolerate partial shade.
Some common varieties known for their stunning flowers include the lavender-hued ‘Niobe,’ and the bell-shaped white flowers of ‘April.’
Step 2: Preparing the Soil and Planting
Clematis, being members of the Ranunculaceae or buttercup family, prefer rich, well-draining soil. Add an ample amount of compost and organic matter to the soil before planting.
It’s also advisable to fertilize it with a balanced fertilizer in April, just at the beginning of the first growing season. The planting hole should be deep enough to bury the first set of leaf stems. This encourages new growth from the base.
Step 3: Providing Support and Training
Clematis vines aren’t self-clinging and require support to grow upwards. Items such as a trellis, arbor, pergola, or fence work well.
Using soft tie twines, gently tie the stems to your chosen support structure. This will guide the plant and encourage upright growth.
Some clematis might need help initially, but soon, they’ll start climbing on their own.
Step 4: Pruning and Maintenance
Many clematis varieties bloom on either new wood or old wood. Pruning clematis depends on this important factor. If your selected variety blooms in early spring, it probably blossoms on old wood. In this case, prune in late spring or early summer after flowering.
For varieties that bloom in midsummer to early fall, they’re likely to flower on new growth. Prune these in late winter or early spring. Always remember to encourage healthy growth by mulching and fertilization.
Common Pests and Plant Diseases for Clematis
- Aphids: Aphids are tiny insects often found on the stems, buds, and undersides of clematis leaves. They suck the sap from the stems and leaves, thereby weakening the plant and diminishing its bloom. Spraying them off with water or a mild pesticide can provide relief to the plant.
- Clematis Wilt: Clematis wilt is a fungal disease that affects the clematis vines, causing the leaves and stems to wilt and turn black. This disease often strikes in late spring or early summer, disrupting the plant’s bloom time. Removal of the affected parts, adequate spacing for air circulation and proper sanitation can limit the spread of this disease.
- Powdery Mildew: Powdery mildew is easily identified by a white powdery substance on the leaf surface. Although it prefers conditions of high humidity and moderate temperatures, it can affect clematis vines in both full sun and partial shade. Treatment includes applying a fungicide and ensuring proper ventilation among the vines.
- Slugs and Snails: Slugs and snails are common pests for many plants, including clematis, notably during the first growing season. They eat new growth which inhibits the plant’s overall health and flowering capabilities. Application of pet-safe slug and snail bait around the base of the plant can help control their population.
Common Plant Problems and Solutions for Clematis
The yellowing leaves in clematis vines are a common issue often due to overwatering or poorly drained soil. To address this, prune the affected stems to stimulate new growth and improve air circulation.
Also, incorporating compost into the soil and adding mulch around the base of the plant can help improve the soil’s water-holding capacity.
Clematis flowers wilting can be a symptom of clematis wilt or stem rot, a fungal disease that strikes in early summer when new wood is at its most vulnerable.
If this happens, cut back affected vines down to the ground and dispose of them away from the garden. It is also essential to increase sun exposure, as clematis varieties thrive in areas with full sun to partial shade.
Brown tips on your clematis leaves may indicate a deficiency of some essential nutrients, often due to a lack of appropriate fertilizer.
Administer a balanced, slow-release fertilizer in early spring and late summer. Remember to water well after applying the fertilizer to avoid burning the plant roots.
If your clematis vines look long and leggy, it may mean they’re not getting enough sun. These natives of North America require full sun to grow to their full potential. If they are not exposed to enough daylight, move them to a sunnier location.
If they’re in-ground plants, you can support them with a trellis, arbor, fence or pergola, letting them climb towards the light using twines.
Failure to Bloom
If your clematis plant does not produce bell-shaped flowers, it could be related to several factors. New clematis vines, particularly during their first growing season, often require more time to establish roots before directing their energy towards producing flowers. Others might not be pruned properly, affecting their bloom time.
Some clematis varieties bloom on both old and new wood, so they need painstaking pruning in late winter or early spring to remove dead wood without damaging flower buds.
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Melissa Pino is a biologist, master gardener, and regular contributor for Planet Natural. Melissa’s work focuses on promoting environmentally-friendly practices, helping people create healthy gardens and finding ways to achieve overall health and wellness.