Clematis are popular climbing plants known for their diverse forms and vibrant blooms. While many varieties offer beautiful additions to a landscape, some gardeners seek options that do not spread aggressively. This article guides you through clematis varieties with contained growth habits, ensuring they enhance your garden without unintended expansion.
Decoding Clematis Growth Habits
Understanding plant growth habits is important for successful gardening, particularly when distinguishing between a vigorous plant and an invasive one. A vigorous plant grows quickly and fills its allotted space, often requiring regular pruning to manage its size, but remains within its defined area.
In contrast, an invasive plant is a non-native species that spreads aggressively, often outcompeting native species and disrupting local ecosystems through rapid spread via self-seeding, rhizomes, or stolons. While some clematis species are aggressive growers, few are truly invasive, such as Clematis terniflora (Sweet Autumn Clematis), known for its rampant self-seeding.
Top Non-Invasive Clematis Varieties
For gardeners seeking clematis without aggressive spread, several non-vining or less vigorous vining types offer beautiful, manageable options. These varieties typically form compact clumps or shrub-like structures, suitable for mixed borders or containers, ensuring they remain within their intended space.
Clematis integrifolia, often called solitary clematis, is a non-climbing, woody-based herbaceous perennial forming a dense, upright to sprawling mound, typically reaching 12 to 24 inches tall. Its solitary, nodding, urn-shaped blue flowers appear from May to July, with continued blooming into September, followed by attractive silvery-green seed heads. This species and its hybrids, such as ‘Floris V’, are excellent for mass planting, rock gardens, or the front of borders, where their non-clinging stems can scramble among other plants.
Another excellent non-vining choice is Clematis recta, also known as ground clematis. This clump-forming herbaceous perennial grows as an upright or sprawling plant, reaching 1 to 1.5 meters tall and spreading 0.1 to 0.5 meters. It produces abundant small, fragrant white star-shaped flowers in large terminal panicles from late spring to early summer, followed by ornamental silvery seed heads. While it can be trained to climb, it often sprawls along the ground or is supported by other plants in wild gardens or meadows. A cultivar like Clematis recta ‘Purpurea’ features attractive purple foliage.
Clematis heracleifolia is a deciduous sub-shrub that grows as a bushy plant forming leafy mounds, typically reaching 2 to 3 feet tall and 2 feet wide. This non-vining clematis produces clusters of small, fragrant, blue tubular flowers in late summer to early fall. It is well-suited for the middle of a sunny perennial border and dies back to an underground rootstock in winter. ‘Mrs. Robert Bryden’ is a good example of this shrubby type.
Many compact large-flowered hybrid clematis varieties offer a less rampant growth habit, suitable for smaller gardens and containers. Cultivars like ‘Hagley Hybrid’ produce abundant, large, shell-pink flowers and are best trained on arbors or fences, or grown through small shrubs. Other examples include ‘Bourbon’ (bright raspberry-red), ‘Rhapsody’ (sapphire blue), and ‘Rebecca’ (stunning red). These varieties, along with ‘Piilu’ and ‘Fleuri’, are vigorous but manageable, typically reaching 6 to 8 feet tall, and are well-suited for containers. ‘Sweet Summer Love’ is specifically bred as a non-invasive version of sweet autumn clematis, offering fragrant cranberry-violet blooms and a more contained growth.
Caring for Non-Invasive Clematis
Proper care ensures non-invasive clematis varieties thrive and provide abundant blooms. Selecting an appropriate planting location is important for their health and flowering. Most clematis prefer a site where their “heads are in the sun and their feet are in the shade,” meaning foliage receives full sun to part shade, while the root zone remains cool and moist.
The soil should be fertile, moisture-retentive, and well-drained, ideally humusy or loamy, as clematis dislike heavy clay. Keeping roots cool can be achieved by planting low-growing groundcovers with shallow root systems nearby or by applying a 2-inch layer of mulch. Regular watering is necessary, especially during dry periods, to maintain consistent soil moisture.
Pruning requirements vary by variety, but many herbaceous and shrubby clematis fall into pruning Group 3. This means they bloom on new growth and should be cut back hard in late winter or early spring, typically to about 12 inches from the ground. This annual pruning promotes strong new stems and abundant flowering.
Why Choose Non-Invasive Clematis
Opting for non-invasive clematis varieties offers several advantages. These plants provide peace of mind, as they will not spread beyond their intended planting areas, helping maintain the garden’s design and structure. This contained growth means less time managing unwanted plant spread, reducing overall maintenance efforts.
Non-invasive clematis support a balanced garden ecosystem by not outcompeting other desirable plants for resources. Their controlled growth allows for harmonious integration within mixed borders, ensuring other perennials and shrubs can flourish alongside them. These varieties offer the beauty and charm of clematis flowers without aggressive tendencies, contributing to a more manageable and enjoyable gardening experience.