Clematis vines grow in a variety of sizes, shapes and hues. Gardeners use the long vines to adorn trellises, mailboxes and light posts, where the flowers erupt in a profusion of vivid color. The number of types and crosses of clematis give gardeners myriad options for just about any season. Although clematis has a reputation for being difficult to grow, according to the Ohio State University Extension, making well-considered garden choices should help ensure the plant’s survival.
Select a site for your clematis plant. Clematis needs at least six hours of full sun each day, although it will also grow well if it receives dappled shade in the afternoon. The Clemson Cooperative Extension recommends an eastern exposure as the best possible location for clematis. Brightly colored flowers may fade if exposed to too much sun.
Test the soil. Clematis requires neutral pH, and the Ohio State University Extension recommends focusing on the pH and phosphorus levels when reading a soil test for a potential clematis bed. Make necessary corrections to the soil to adjust pH and nutrient availability.
Dig a bed 2 feet deep and 3 feet wide. Incorporate compost or well-rotted manure to fill at least one-third of the volume of the bed.
Cut back stems to 12 inches. Dig a hole in the bed large enough to fit the plant's entire root system and plant the crown 2 inches below the soil line. Cover with soil.
Add mulch around the plant 2 inches deep. According to the Clemson Cooperative Extension, clematis vines like "their heads in the sun and their feet in the shade," so you'll need to keep the root area cool. Shallow-rooting groundcover or perennials around the base of the clematis will also keep the roots cool and moist.
Install a trellis or another object for the clematis to climb. Clematis needs thin structures that it can wrap its petioles around. Clematis can also grow to drape across woodpiles.
Provide at least 1 inch of water per week if rainfall is inadequate.
Fertilize annually to promote strong growth. The Ohio State University Extension recommends using 3:1:2 or 4:1:2 ratio fertilizers and applying a 1/2 lb. per 50-foot area around the plant.
Prune clematis annually to encourage new flowers. When to prune depends on the season in which your clematis flowers, according to University of Illinois Extension educator Sandra Mason. Prune clematis vines that flower in April or early May after they bloom. In March, you should prune clematis that bloom in late May, only to remove dead wood. Finally, you can prune varieties that bloom in the summer at any time, but they are best pruned back to 18 to 24 inches in spring.