Determining which group your clematis belongs to can be a bit tricky, but there are a few key characteristics you can look for to help you identify it. Here are some tips to help you figure out which group your clematis falls into:
1. Blooming Time: One of the easiest ways to determine the group of your clematis is by its blooming time. Spring-blooming clematis, which belong to Group 1, typically flower on old wood. This means that the buds for these flowers are formed in the previous growing season. Repeat-blooming clematis, belonging to Group 2, bloom on both old and new wood. They produce an initial flush of flowers on old wood in spring, followed by additional blooms on new wood throughout the growing season. Summer and fall-blooming clematis, grouped as Group 3, flower on new wood. These clematis varieties produce their buds on the current season’s growth.
2. Flower Shape and Size: Another characteristic that can help you determine the group of your clematis is the shape and size of its flowers. Group 1 clematis typically have large, single flowers with simple shapes. They may have four to eight petals and come in a variety of colors. Group 2 clematis often have larger flowers than Group 1, and they can range from single to semi-double and even double blooms. These varieties often have more intricate flower shapes and a wider color range. Group 3 clematis tend to have smaller flowers compared to the other groups, and they can be single or semi-double. The flower shapes are often more delicate and come in a range of colors.
3. Pruning Requirements: Each clematis group has specific pruning requirements, which can also help you identify its group. Group 1 clematis should be pruned after flowering, as they bloom on old wood. Group 2 clematis require a light pruning in early spring to remove any dead or weak stems, followed by a more thorough pruning after the initial spring bloom. Group 3 clematis should be pruned in late winter or early spring before new growth begins, as they bloom on new wood.
4. Growth Habit and Vigor: Observing the growth habit and vigor of your clematis can provide additional clues about its group. Group 1 clematis tend to have a more compact and upright growth habit, while Group 2 clematis can be more sprawling and vigorous. Group 3 clematis are often the most vigorous of the three groups, with a tendency to grow taller and produce more abundant foliage.
5. Consult Reference Materials: If you’re still unsure about the group of your clematis, it can be helpful to consult reference materials such as gardening books, websites, or catalogs. These resources often provide detailed descriptions, photographs, and even group classifications for different clematis varieties. You can compare the characteristics of your clematis with the information provided to make a more accurate determination.
Remember that clematis varieties can vary, and some may exhibit characteristics that overlap between groups. It’s also worth noting that newer hybrid clematis varieties may not fit neatly into the traditional group classifications. If you’re unsure or have a unique clematis variety, it’s always a good idea to consult with a knowledgeable gardener or nursery expert for guidance.
