Growing Clematis

Shopping for Clematis: The old adage "Bigger is Better" could not apply more than to those hunting for clematis; the roots, that is. A one year-old rooted cutting will probably not produce flowers of any note for 2 - 3 years as I've learned from personal experience. Sometimes to get a certain variety, it is necessary to purchase smaller plants, but don't if you can help it. It is also not advisable to plant out these smaller clematis as their survival rate is questionable. Pot them up into gallon size containers and grow them for at least one year, possibly more depending on the variety and how quickly it grows. Be sure to sink the pot in the ground for winter protection in Zone 4 - 5. Look for plants with 2 - 3 basal shoots rather than one single, even if it has a flower! The more basal shoots, the better. That being said however, it’s best to buy in bloom as you might not get the color or the clematis variety the tag says it is. Growers make mistakes just like the rest of us and waiting 3 - 4 years for that special clematis to bloom, only to find it’s not what the tag said it was is no fun. It’s a good idea to buy from a reputable grower or nursery. 

Choosing the site for your clematis is the next task. Most like their heads in the sun and feet (roots) in the shade. Clematis require less sun than roses and they can be planted in partial to full sun situations. What they don’t like is wind, which can snap or damage the canes, making it look like the tops of the vine are dead. This can be avoided by strapping them to a trellis or supporting them by letting them grow into a companion rose, shrubs or trees. As long as their roots are kept moist and the soil has good drainage, they will thrive in your garden. Young gallon size plants should be planted in a hole that is at least double the size of the pot and about 4-6” deeper than the pot. Soak the roots in a bucket of water for about ten minutes just before planting while you dig the hole. At the bottom of the hole you can apply a layer of compost or organic fertilizer to enrich the soil. Be sure to cover this with a thin layer of soil before placing the roots of the clematis in the hole so as not to burn the tender roots. Plant the clematis about 3 - 4" deeper than the crown of the plant; the hole with your native soil amended with compost to help with both drainage and holding more moisture in the soil. Top dress with more organic fertilizer or compost and water well. Keep the soil evenly moist throughout the growing period and either use mulch or a low growing plant in front of the clematis to keep the roots shaded. No rocks as these heat up the soil and attract snails and slugs, the number one enemies of clematis. Not all clematis climb on their own. Some have a petiole or leaf stalk that will wrap around close slender objects and the following leaf buds climb higher from there. Some herbaceous clematis do not have such petioles so they must be tied or propped up to remain vertical or used as ground covers. Read the tag or check with the dealer to know what sort of trellising you may be in for. 

To Trellis or not to Trellis? On a recent trip to Swan Lake in Ferry County just above Colville, Washington, we observed native Clematis columbiana growing in the wild. Mother Nature is the gardener here and she knows her stuff. Old logs, young Douglas firs, Alder saplings, anything the clematis could cling to, so they could lift their heads towards the sparse sunlight. As long as the support is narrow and strong enough to hold the weight of the vines, it works. If you dreamt of covering your white picket fence with clematis, you can tap some nails up the posts and use wire or fishing line to train the clematis up to the top. Use your imagination! Remember before you get carried away buying or making an elaborate trellis, the clematis will quickly establish and cover all your work! The genus Clematis is divided into two groups of cultivars: 

Large Flowered and Small Flowered. These are both divided between cultivars that are early flowering and late flowering. Sounds easy, but it gets a bit trickier from there. Large flowered/ Early flowering clematis bloom on old wood, hence, pruning group two. (Asao, Guernsey Cream, Belle of Woking). Large flowered/ Late flowering clematis bloom on new wood; pruning group three. (Hagley Hybrid, Perle d’azur, Prince Charles). Small flowered/ Early flowering clematis bloom on old wood; pruning group one. (Alpinas and Macropetelas are hardy for our area.) Small flowered/ Late blooming varieties flower on new wood; pruning group three. Integrifolias, Viticellas, Tanguticas, Texensis-Viorna and other species such as Flammula and Vitalbas. Many of the smaller flowered clematis bloom longer and have more blooms just not as showy. Your choice. Plant according to when you want your blooms and check the blooming period of your clematis to see if it will be sending you more later if you dead head and or pinch it back. The tag should say so, but check reports from others via the internet. Try to find someone who is closer to your zone and growing area as well. Clematis in California grow like weeds all year long!  Many growers will have a number or a letter specifying the pruning group that a particular clematis variety belongs. Pruning Group one or A: means little or no pruning is necessary and that the clematis blooms on old wood. These varieties can be pruned if you would like them to look more tidy, but it should be pruned after the early spring flush or you’ll cut off their blooms. Pruning Group two or B: These clematis bloom in two flushes; late spring or early summer and again in the fall. They bloom on old and new wood and should be pruned in late spring when you can see where the new leaf buds are emerging. To cut them too far back before that time will mean less bloom. Pruning Group three or C. This group often blooms mid-summer to late summer or often into fall. Although these clematis can be pruned to 12" some varieties such as the Viticella Group can be pruned to extend their flowering period by pruning just ½ of their canes, thus prompting blooms on the new wood, but allowing blooms on the old wood to flower first. Remember: Even if you prune your clematis the wrong way or not at all, it will continue to grow and may even surprise you by how well it thrives in spite of your care! Just keep watering and fertilizing and your clematis will be happy.

Classifications: The genus Clematis is divided into two groups of cultivars: Large Flowered and Small Flowered. These are both divided between cultivars that are Early flowering and Late flowering. Sounds easy, but it gets a bit trickier from there. Large flowered/Early flowering clematis bloom on old wood, hence, pruning group 2. (Asao, Guernsey Cream, Belle of Woking). Large flowered/Late flowering clematis bloom on new wood; pruning group 3. (Hagley Hybrid, Perle d’azur, Prince Charles). Small flowered/early flowering clematis bloom on old wood; pruning group 1. (Alpinas and Macropetelas are hardy for our area.) Small flowered/Late blooming varieties flower on new wood; pruning group 3. Integrifolias, Viticellas, Tanguticas, Texensis-Viorna and other species such as Flammula and Vitalbas. Many of the smaller flowered clematis bloom longer and have more blooms, just not as showy. Your choice. Plant according to when you want your blooms and check the blooming period of your clematis to see if it will be sending you more later if you dead head and or pinch it back. The tag should say so, but check reports from others via the internet. Try to find someone who is closer to your zone and growing area as well. Clematis in California grow like weeds all year long! 

Unidentified Clematis: Either you planted your clematis with a tag and your dog or small child ate it, or you've inherited this garden from the former gardener and they planted it and their dog or small child absconded with the tag. Never mind. Observe and document (yes, be anal) the time the clematis comes into bloom (what month, not the time of day) and if it repeats later in the fall or continues for 2-3 months. This helps determine the growth habit and which pruning category would best match this plant.