All About Clematis
Clematis are one of the most rewarding plants a gardener can grow. Once established, this vine will grow up and present an intense amount of flowers. There are more than 300 species of clematis that hail from around the world, so there's bound to be a species and variety that's right for your yard. In fact, there may be so many that can grow where you live, the choices can seem almost daunting!
Which Clematis should you choose?
When first choosing clematis, look for types hardy for your area. The species types tend to be the ruggedest clematis, while the large-flowered hybrids may need a bit more pampering. Then select for flower color and bloom time. If you select wisely, you can have clematis blooming in your yard from spring until frost.
Consider the types of flowers you like when buying your clematis vine. The flowers can be star-like and either small or large. Colors range from pure white to deep purple. There are also species, such as 'Betty Corning', that has nodding, bell-shaped flowers. Some clematis have lantern shaped flowers, such as the yellow flowered 'Bill MacKenzie'. Others have small, dogwood-shaped flowers, such as the creamy pink 'Little Nell'.
Bloom time is important as well. Some early-blooming clematis include purple-striped 'The President' and 'Multi Blue', with its bold stamens and sepals that leave behind visual interest after the bloom itself has faded. The Armandii types are evergreen and good choices for warmer climates. For early to midsummer blooms, look for the large flowered hybrids. This large group includes 'Niobe' (red), 'Jackmanii' (bluish-purple), 'Nelly Moser' (bicolor mauve and pink), and 'Snow Queen' (white). An advantage of these hybrids is if you're diligent about deadheading the blossoms after the first flush of flowers, you'll get a second flush later in summer.
Come fall, look for clematis varieties that provide colorful flowers, but also interesting seed heads. These can be left on the vine to add winter interest to your garden.
Some good choices include the native Virgin's bower (C. virginiana), C. jouiniana 'Mrs. Robert Brydon' (blue), and C. tangutica 'Helios' (yellow). The common Sweet Autumn Clematis ternifolia (paniculata), has very fragrant, small white flowers in profusion in fall. As it can self-sow rampantly, you'll need to be diligent about deadheading and pruning so that you can keep it in bounds.
There are also shorter, bushy types of clematis that grow only a few feet tall. These are excellent in small-space gardens or even containers. Look for shorter clematis varieties such as 'Bushy Blue Bell', 'Rosea Bush', and 'Mongolian Gold'.
A good evaluation of many northern clematis varieties for their vigor, flowering quality and disease resistance was undertaken by the Chicago Botanic Garden.
Clematis Growing Tips
Once you have selected your clematis, then it needs to be planted. Most clematis grow best with at least 6 hours of direct sun a day. The soil needs to be rich in organic matter and nutrients, but also well-drained. A healthy plant will have 6 to 8 strong stems growing from the base. Mulch to keep it cool. When planting, place the transplants a few inches deeper in the soil than they are in the pot. This will help protect the crown.
Clematis need support when growing
Your clematis may need help getting attached to the trellis, arbor, pergola, lamp post or whatever structure it will grow up. Attach the clematis vines loosely to twine or to small-guage wire fixed to the larger structure. Once entangled in the structure, these smaller supports won't be needed. Be patient. Don't be surprised if your clematis vines take a few years to really start growing fast.
The old adage for vines is: “the first year they sleep, the second year they creep, and the third year they leap”. It's best to let the roots get established in the soil the first few years to support much larger growth and flowering in the future.
Companion Plants for Clematis
While clematis have traditionally grown up walls, wooden structures, posts and wire fences, there are other ways to use clematis in the landscape. Certainly, the smaller vining and bush types work well in container gardens and rock gardens. They won't overwhelm the other plants. Try clematis on metal trellises as a beautiful backdrop in a perennial garden.
However, let some clematis run wild. Try growing 'Niobe' large flowered clematis at the base of some juniper bushes in your yard. Help the vine get started in the juniper bush, then let it run. It's always a delight in midsummer to see bright red flowers randomly popping out from the juniper bush. Depending on the aggressiveness of your clematis vines, you can repeat this technique on small trees, tree stumps and any open-branched shrub. Growing clematis among evergreens is attractive because they give a nice backdrop to the colorful clematis flowers.
You can even let some clematis, such as Clematis Praecox, run horizontally down a bank or slope as a ground cover. It will flower among the plantings creating a surprising visual effect. Some of these ground cover types are so aggressive they will crowd and shade out weeds. But be careful they don't spread into other gardens.
About the Author: Charlie Nardozzi is a nationally recognized garden speaker, author, consultant, radio and TV show host. He delights in making gardening information simple, easy, fun and accessible to everyone. Visit his website, GardeningwithCharlie.com for how-to gardening information, and for more about Charlie.
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