How to Grow Clematis: A Complete Guide to the Queen of Climbers

Every flower gardener should experience the joy of growing clematis. If you already have one gracing your garden, you're likely planning where to plant another. New to these stunning vines? Read on to discover how easy it is to succeed with the "queen of climbers."

The Essex Trellis features an unusual parasol shape. Vines grow up and over the top, then drape gracefully for a stunning display.

A well-grown clematis in full flower is a sight to behold.

Selecting the Right Plant

Until recently, only a handful of clematis cultivars were widely available in the U.S. Traditional favorites included 'Jackmanii', 'General Sikorski', 'Henryi', and 'Comtesse de Bouchard'. Today, clematis has become a hugely popular perennial, and the average garden center offers dozens of choices.

When choosing a clematis, consider mature height, flower form, and color. Vigorous 10- to 20-foot varieties are perfect for large spaces, while compact types thrive in small gardens or patio containers.

The standard clematis flower has six or seven petals spanning 5-6 inches. You'll also find cultivars with smaller blossoms, double flowers, and charming bell-shaped blooms. Colors range from white to wine red, lavender to deep purple, with even a few yellow varieties.

Some trellises are purely ornamental, but the Jardin Flower Trellis combines classic Tudor arches with a simpler design that makes climbing easy for clematis.

Clematis vines take several years to mature and flower vigorously. For faster results, buy a plant at least two years old in a quart or gallon pot. Choose a robust, vigorously growing plant over one with a pretty picture tag but weak growth.

Where to Plant

Pick a sunny spot before bringing your clematis home. While some cultivars like 'Nellie Moser' and 'Henryii' tolerate partial shade, all need at least six hours of sun daily for peak performance.

Clematis prefers moist, well-drained soil with a neutral to slightly alkaline pH. If your soil is acidic, amend it periodically with limestone or wood ash. Dig a generous hole, incorporating plenty of compost and granular organic fertilizer.

Handle the plant gently—roots, crown, and emerging vines break easily. Plant slightly deeper than in the pot, so the first set of true leaves sits just below the soil surface. Water weekly the first season to establish the plant. Mulch around the base to conserve moisture, but keep mulch several inches away from the crown where vines emerge.

Clematis thrives with cool roots and warm sun on foliage. Mulch or low-growing perennials help keep the root zone cool.

Providing Support

Most clematis are born to climb. The growing tip searches for something to grasp; without support, it stops growing. Provide a climbing structure from day one.

Companion plants like pale-purple baptisia keep the clematis root zone cool.

Unlike pole beans or morning glories that twine around supports, clematis climbs by wrapping its leaf stems around them. These leaf stems are short, so anything thicker than ½ inch is too wide. Ideal supports include twine, fishing line, wire, thin branches, wooden dowels, or steel rods. More grabbing opportunities mean better climbing—add twine "helper lines" or cover your trellis with netting.

Depending on plant vigor and trellis type, you'll likely need to do some "trussing" during the season to keep vines attached. Fishing line and twine work well for this.

Pruning and Care

Clematis pruning needs vary. Some flower on last year's growth (avoid cutting to the ground in spring), others on current-year vines (can be cut back annually). Instead of memorizing rules for each cultivar, use this common-sense approach: leave prior year's growth until mid-spring. Prune only when you can distinguish dead vines from those leafing out.

The Nearly Invisible Netting helps clematis climb trellises with wide crosspieces. Biodegradable netting is another option.

A happy clematis produces abundant flowers and foliage. Feed well for health and vigor. In early spring, apply a shovelful of compost and a handful of granular organic fertilizer around the plant. Supplement once or twice during the growing season with water-soluble organic fertilizer.