By Kerry Ann Mendez
Clematis, sometimes referred to as the Queen of Vines, will offer astonishing color in the landscape. The flowers can be single, multi-petal or bell-shaped and come in red, pink, purple, lavender, blue, white, yellow and multi-color. Clematis will bloom best in sun to part sun and range in hardiness from Zones 3-8.
All Clematis like nutrient-rich soil. When planting, dig a hole twice as wide and deep as the pot (this is not a typo!). Mix organic matter (i.e. compost) into the soil that was removed. Backfill the hole halfway with the amended soil and set the Clematis root ball on the mound so the crown (the point where the stems meet the roots) is a few inches BELOW the soil level. Tip the plant (up to a 45 degree angle) in the direction of its support and then backfill with the remaining soil and water in well. Fertilize with a granular organic fertilizer like Espoma Plant-tone once a year in spring for best results.
Now to the real reason for this article - how to prune Clematis.
Clematis are grouped into three groups based on pruning requirements: Group 1, 2 or 3.
Group 1: These are the earliest to bloom in spring. They only set flower buds on old wood (the previous year's stems). Pruning should be done immediately after the vine has finished blooming.
Group 2: These usually start blooming in late spring. They bloom on both old and new wood (the current year's growth) and should be pruned lightly in late winter or early spring when green leaf buds begin to swell on the stems. Prune just above the swelling buds - either those higher or lower on stems depending on the height desired. A second pruning can be done just after the flowers finish, but before a second round of flowers arrive later that summer. This group has the largest flowers, with some reaching 5-8" across. 'Diamantina' is in this group.
Group 3: These usually start blooming in early summer, with some flowering even later in the season, and will only set flower buds on new wood. In late winter or early spring, the stems can be pruned hard to within a foot of the ground. Patio Clematis (compact varieties that usually grow between 3-6 feet) are also in this group. Sweet Autumn Clematis (Clematis paniculata) is in this group.
If you are not sure which group your Clematis is in, I recommend this Fine Gardening article that lists many of the commonly sold Clematis by group. We also list the Pruning Groups here on our website in our plant catalog.
Estabrook's carries Group 2 and 3 Clematis, including Patio Clematis.