Clematis (Clematis 'Rouge Cardinal')
Spectacular Clematis 'Rouge Cardinal' offers stunning red summer blooms (June-Sept). A hardy, low-maintenance vine for zones 4-8.
Complete Plant Information
Overview
Clematis ‘Rouge Cardinal’ is a highly valued, large-flowering, deciduous vine prized for its intense, deep-red summer display. This semi-woody hybrid belongs to the Jackman group, offering reliable performance and dramatic vertical interest in the garden from early summer well into autumn. Providing consistent color, this variety of Clematis quickly covers supports, adding architectural height to structures.
As a vigorous climber, Clematis ‘Rouge Cardinal’ requires sturdy support to showcase its 8 to 12-foot reach. Despite its dramatic blooms, this Clematis cultivar is considered low maintenance once established, making it accessible to many gardeners seeking vertical impact without demanding constant attention. Its presence dramatically enhances fences, arbors, and trellises throughout the summer season.
Gardeners seek out Clematis for their sheer visual splendor, and ‘Rouge Cardinal’ delivers with profuse flowers that span 4 to 6 inches across, accented by contrasting brownish-yellow stamens. Ensure its roots stay cool and shaded while the foliage enjoys the sun to maximize the health and flowering potential of this stunning vine.
Fast Facts
- Plant Family: Ranunculaceae
- Plant Type: Vine
- Hardiness Zones: USDA Zones 4-8
- Size at Maturity:
- Height: 8-12 ft
- Spread: 3-6 ft
- Bloom Time: June to September
- Bloom Description: Red with brownish-yellow stamens
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
Planting should ideally occur in spring or early fall in fertile, well-drained, medium-moisture soils. The most critical cultural note for Clematis ‘Rouge Cardinal’ involves microclimate management: site the vine so the flowering portions receive full sun to partial shade, but ensure the root zone remains cool, shaded, and uniformly moist. Shading the base of the vine with low-growing perennials or small shrubs is an excellent technique practiced by seasoned Clematis growers.
Watering should be consistent, maintaining medium moisture levels; never allow the soil around the roots to dry out completely. Clematis vines inherently need a trellis, arbor, or other sturdy vertical support structure to twine upon for upward growth. A thick root mulch is highly appreciated as it helps retain moisture and keeps the roots cool throughout the warm growing season.
Pruning this variety requires flexibility, as Clematis ‘Rouge Cardinal’ can generally be managed as either a Group 2 or Group 3 vine. Group 2 blooms on both old and new wood, while Group 3 flowers only on new wood and can be cut back hard in late winter or early spring. Consult specific guidelines for your growth habit, but aggressive spring pruning is often suitable for encouraging vigorous new growth.
Landscape Uses
The primary strength of Clematis like ‘Rouge Cardinal’ lies in its ability to provide magnificent vertical accents in the garden space. These vines are perfect for training upward along walls, fences, or through the supports of an arbor, where their vibrant red blooms can be viewed from multiple angles. They create excellent architectural height, adding structure even when dormant.
Beyond traditional climbing, these Clematis varieties function beautifully when allowed to sprawl. Consider planting them to scramble over established, non-prickly shrubs, softening their structure with cascading foliage and vivid color. They also perform well when used as a dramatic focal point in large containers, provided they have adequate support anchored within the pot.
For dynamic border design, pair the intense red of Clematis ‘Rouge Cardinal’ with contrasting cool colors, such as silvery foliage plants or soft blue/purple companion flowers that bloom concurrently. This allows the rich color of the vine to truly stand out against the backdrop.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Clematis is a complex genus featuring over 250 species, primarily woody deciduous vines that climb via twining leaf stalks. Cultivated plants are typically categorized into three pruning groups based on which wood produces flowers. Specific to this variety, ‘Rouge Cardinal’ is a deciduous, large-flowering, semi-woody climbing clematis vine of the Jackman group, known for its profuse summer bloom and rich red flowers measuring 4-6 inches across.
Tolerances
- Deer
- Black Walnut
Potential Problems
Clematis vines are susceptible to several significant issues, most notably wilt or stem rot, which can prove fatal to the plant if not addressed quickly. Fungal diseases, including powdery mildew and leaf spots, commonly appear, especially in conditions with poor air circulation. Monitor closely for spider mites, aphids, slugs, snails, scale, and earwigs, which can damage foliage and young stems. Ensuring proper sunlight for the vine’s top growth and keeping the roots cool and shaded through mulching are vital preventative measures against stress-related diseases.
Frequently Asked Questions
What hardiness zones is Clematis ‘Rouge Cardinal’ suitable for?
This durable Clematis variety performs best in USDA Hardiness Zones 4 through 8.
How large does Clematis ‘Rouge Cardinal’ grow?
When mature, this climbing vine typically reaches a height between 8 and 12 feet, spreading 3 to 6 feet wide.
When does Clematis ‘Rouge Cardinal’ bloom?
You can expect the vibrant red flowers of Clematis ‘Rouge Cardinal’ to appear from June through September.
What sun exposure does Clematis ‘Rouge Cardinal’ need?
This plant prefers a location that provides full sun to part shade exposure.
Conclusion
Clematis ‘Rouge Cardinal’ remains a favorite for gardeners seeking reliable, dramatic vertical color, delivering stunning red flowers throughout the peak summer months. Its relatively low maintenance paired with its striking visual impact makes this Clematis a must-have climber for walls and supports. Before planting, confirm you can provide the necessary cool, shaded root run and a sturdy structure to best enjoy the magnificence of this renowned Clematis.
Companion Planting
Choosing the right partners is key to maintaining the cool, moist root environment Clematis demands. Plant ground covers like Hostas, low-growing Geraniums, or creeping Phlox around the base of the vine to shade the soil and prevent overheating. Avoid aggressive perennial spreaders that might compete heavily for water or physically smother the young base shoots of the Clematis.
Consider using upright, non-woody companions like tall ornamental grasses or densely mounding salvias to fill in the space beneath the vine. This strategy solves the “cool feet, hot head” requirement perfectly, ensuring the lower parts of the vine are obscured in shade while keeping the radiant red blooms visible against the sky.
Seasonal Care Calendar
Early spring is the crucial time for pruning decisions regarding Clematis ‘Rouge Cardinal’, as it often responds well to Group 3 pruning (cutting back to a pair of strong buds above ground). Immediately after last frost, apply a balanced, slow-release fertilizer around the drip line, keeping it away from the main stem.
Summer care focuses heavily on consistent hydration, especially during dry spells, to prevent the soil from drying out at the root zone. In hot climates, monitor for signs of stress or wilting, which usually indicate the roots are becoming too warm or dry, necessitating increased mulching or supplemental shade application.
As temperatures drop in the fall, cease heavy fertilization. If you notice any stems showing signs of disease or weakness, this is a good opportunity to selectively remove them before winter sets in, preparing the vine for its spring pruning cycle.
