It’s no wonder Clematis are often called the “Queen of all Vines”—with their dazzling blooms, they truly are the stars of any sunny perennial garden!
While these gorgeous climbers can sometimes be a bit fussy to grow in Alberta, don’t let that discourage you.
In this blog, I’ll walk you through some helpful tips for caring for Clematis and offer simple advice on how to prune them, so you can enjoy their spectacular flowers year after year.
How to Care for Clematis
Clematis have 4 simple needs:
1. Clematis Need a Sunny Place to Grow
Clematis is a sun lover, requiring a minimum 6 hours or more to thrive. Clematis enjoys a break from the sun in the later afternoon to give it a respite from the heat and a little less intense sun at that time of day helps reduce flower fade on the older blossoms.
Be on the lookout for things that will compromise sunlight exposure to your Clematis. A neighbour’s house or garage next door, house eves, trees, fences, pillars, and posts can all block sunlight.
2. Clematis Like to Grow in Moist Soil
Clematis require a rich soil base that holds moisture but drains well.
Soggy soil can lead to death of a Clematis because its roots tend rot if they are too wet for too long.
To prevent overwatering, always check Clematis before hydrating the soil. An easy way to do this is to stick the entire length of your index finger into the soil and if you find that the soil is dry at the tip of your finger, or at the first knuckle, it’s time to water.
Monitor Clematis closely well during dry spells and water deeply.
3. Vining Clematis Need Something to Climb
Being a vine, some Clematis can grow up to 20′ (6 m) long. Clematis have built-in long stems attached to their leaves, called petioles that twist around support structures.
Clematis climb support structures by wrapping their long petioles like arms around structures as they climb. Because the petioles are 4-6″ (10-15 cm) long, you need to watch that what you put in place is narrow enough for them to grasp onto.
Fences with wide boards and house siding, smooth or rough, will not work for Clematis, they will need some finer mesh or galvanized wire, like chicken wire to attach to.
Other supports that Clematis easily climb are trellises, obelisks, and arbors with narrow structures.
4. Clematis Need to be Fertilized Regularly
Fertilize Clematis in early spring because they are actively growing. This is a different from other perennials because most perennials don’t need much fertilizer.
Feed Clematis as they emerge in spring with a slow release fertilizer with an formulation of 10-10-10 and during the growing season, apply a lower nitrogen formulation like 5-10-5 or15-30-15 to encourage bud and flower formation every 4-6 weeks, until the Clematis plant is in full bud.
Stop fertilizing when the Clematis is in full bud because too much fertilizer can cause the Clematis to lose its buds to make way for leafy foliage growth.
Clematis Growing Myth: Clematis Need Cool Roots
You’ve probably heard the gardening advice that Clematis like “cool roots and a warm head.” While this saying contains some truth, it’s often misunderstood.
Clematis do perform best when their vines and flowers receive plenty of sunlight—the “warm head” part. However, the idea that their roots require special cooling measures is somewhat exaggerated. What Clematis really need is soil that stays evenly moist rather than dry and overheated.
What’s True
Plenty of Sun for Blooms
For the best flowering, Clematis generally need around six hours or more of sunlight each day.
Moist Soil Matters
Clematis roots prefer soil that remains consistently moist. When the soil doesn’t dry out, the root zone naturally stays cooler and healthier.
Planting a Little Deeper Helps
Clematis benefit from being planted slightly deeper than they were in their nursery pot—about 7-10 cm (3-4 inches) below the soil surface. This can help protect the plant from Clematis wilt and encourages stronger growth from the base.
Mulch Makes a Big Difference
A 7-12 cm (5-7 inches) layer of mulch, such as bark chips, compost, or shredded wood, helps the soil retain moisture and keeps the root zone from heating up too quickly.
Related: What is Mulch? Making Gardening Magic with Mulch
What’s Often Misunderstood
Roots Don’t Require Shade
Clematis roots don’t actually need to be shaded from the sun. The real issue is dryness—if the soil stays moist, the roots will usually remain cool enough.
Extra Barriers Aren’t Essential
Some gardeners place rocks or plant dense perennials directly over the root zone to keep it shaded. While this can work, it isn’t necessary if the soil is well-watered and mulched.
Clematis Aren’t Extremely Heat-Sensitive
Although they appreciate cool, moist soil, many clematis varieties tolerate warm climates quite well. In fact, some species originate from naturally warm regions.
About Pruning Clematis
Why Prune Clematis?
A pruned clematis is a healthy Clematis.
Trimming Clematis controls the growth pattern and improves overall Clematis performance by:
- Improving air circulation throughout the vine
- Providing better light exposure all over the plant
- Stimulates fresh growth
- Boost flowering
When to Prune Clematis
Clematis are broken up into 3 different pruning classes and the label included with each Clematis plant should indicate which class they are.
The pruning groups are divided as A,B, & C – or 1,2, & 3. Group A is the same as Group 1, Group B is the same as Group 2, and Group C is the same as Group 3.
That being said, not all Clematis fit neatly into pruning groups. Large-flowered hybrid, like viticella, texensis, and integrifolia Clematis don’t all behave identically within their pruning groups. Be vigilant to check tags for pruning instructions for each specific Clematis. If the information is lacking, do an internet search for the variety.
Let’s look at each Clematis Pruning Group individually:
When to Prune Clematis Pruning Group A
Group 1 Clematis blooms on old wood from the previous year’s growth, while not needing routine hard pruning, this group does benefit from pruning that focuses on:
- removing dead, damaged, crossed, and rubbing stems after flowering
- thinning to reduce woody stem congestion and improve air circulation
- shaping and size management following flowering
While pruning group doesn’t equate to hardiness, Group A is typically a collection of more tender perennials that grow in warm zone 6 & 7 growing spaces, several species including Clematis alpina and macropetala are reliable to zone 3, and possibly zone 2.
When to Prune Clematis Pruning Group B
Clematis Group B is a large flowering type that is divided into two subgroups:
- Clematis Group B1: Initially emerges and flowers on older stems in spring and reblooms on new growth in the late summer.
- Clematis Group B2: The blossoms occur on older stems and new growth simultaneously.
This can be a challenging group to grow because they depend on old wood survival, which can be challenging in areas that are particularly vulnerable to freeze-thaw cycles, the drying effects of Chinook winds, late killing frosts, and open prairie winter winds that can cause delayed, reduced flowering, or no flowering.
It is recommended to plant Group 2 Clematis in sheltered, protected microclimates, or given winter protection to reduce the negative effects of winter weather. Spring flowering on Group 2 Clematis are considered a bonus in Alberta, not a guarantee.
For pruning both subgroups, there are 2 options:
- Lightly prune a few stems in the spring to encourage strong buds & to promote branching & blossoms on new growth while letting other old stems grow to produce the spring bloom
- OR, you could prune the entire plant back every two years and miss the spring flush
Varieties that belong to this group include Nelly Moser, Henryii, Multi Blue, Vancouver, and The President.
When to Prune Clematis Group C
Clematis Group C is a later bloomer and only flowers on new growth. Once they get going, they will bloom from July until frost in the autumn.
Check Clematis variety tags carefully, you will find cultivars ranging from Zone 3 to Zone 6. Snow cover and fall dieback make these Clematis some of the most hardy varieties to grow in Alberta.
Prune back this group hard in early spring once leaf buds are visible but before active growth begins. Count up the stem to four leaf nodes from the ground (this will probably come to 30 cm or 12″ from the soil line).
This pruning will encourage branching, thicker growth, and more flowering.
Jackmanii, Jackmanii Superba, Polish Spirit, Prince Charles, and Comtesse de Bouchaud are varieties in pruning group C.
Keep an eye out for Clematis Viticella group, Texensis hybrids, and the Integrafolia group.
Pruning Clematis Step by Step
Trimming Clematis is quite simple; all you need is a few simple tools and you will be on your way!
The tools you will need to trim a Clematis include:
- Hand Clippers – freshly washed in warm, soapy water to prevent the transmission of bacteria or any other damaging soil borne infection.
- Fasteners to attach Clematis to the Support Structure – hook & loop tape or another gentle tie will work well for this
How to Prune a Clematis
- Determine where the Clematis needs to be trimmed. Some guidelines recommend trimming Clematis at12″ (30 cm) above the ground, while other Clematis types have different requirements. Once you know where you need to trim, get your clippers out.
- Trim the Clematis stem by stem so you cut it back in the right place.
- Cut the Clematis just above the leaf nodes as seen in the photo. Leaf nodes are the spot on the stem where the leaves come out of the stem. Clematis have two leaves that come out of the stem opposite one another.
- Once you have finished pruning, collect all the stems and leaves and remove them from the Clematis growing area. Keeping the growing space clean from decomposing Clematis material helps reduce the spread of disease.
- Wash your clippers after you are done so they are clean and ready for their next task.
To Sum up the Care & Pruning of Clematis
Clematis are truly special flowers, and setting them up for success starts with choosing the right spot in your garden.
After planting, there are just a few basics to keep in mind. Make sure your Clematis isn’t planted too shallow, provide good drainage, and avoid letting the roots stay too wet—these simple steps make a big difference in keeping your plant healthy and happy.
While the idea of three different pruning groups might sound confusing at first, the good news for Alberta gardeners is that most Clematis here fall into group 2, which takes the guesswork out of pruning.
Once your Clematis is established, you can look forward to years of vibrant blooms and lasting beauty in your garden.
More to Explore
- 5+ Clematis Varieties That Work Well in Alberta
- A Step by Step Guide on How to Plant Clematis
- 10+ Amazing Annual and Perennial Flowers to Grow in Full Sun
- Understanding Perennial Seasons of Bloom [+ Perennial Flowering Reference Chart]
- 6+ Front Door Planter Ideas to Make Your Entrance Shine
Thank you to Colin Russell for editing assistance!
© Sharon Wallish Murphy, Gardening with Sharon
