ABC: All ‘Bout Clematis
Clematis are a surprisingly diverse group of vines and ramblers that are both a landscape design favorite as well as a source of confusion given the sheer variety available.
Common questions about clematis focus on their best planting and growing location, the volume of flowers they could produce, and the best time to prune them for optimal vigor.
As a group of vines, many clematis are surprisingly cold hardy and durable choices (most to Zone 4), provided they become properly established; you’ll often see clematis pushing new growth as early as early March!
Garden varieties are mainly composed of robust climbers, but they also include shrubby upright types, compact growers good for containers, and very effective ground covers. Clematis are tolerant of partial sun spots in the garden. They prefer to have shade over their roots with a place to bask their foliage in morning to early afternoon sun.
As they vary regarding their peak bloom times – some bloom on old wood, others only on new wood, and some a combination of both – how to prune them is an important consideration to ensure you’re helping them give you all the flowers they can.
Clematis varieties can be divided into three categories based on their bloom season and pruning requirements:
- Group 1: strictly spring bloomers
- Group 2: late spring/early summer bloomers with a sporadic rebloom
- Group 3: late summer and into fall bloomers
Each group has its optimal blooming season and requires a specific pruning method to ensure the best chance for flowers.
GROUP 1: SPRING BLOOMERS
Spring blooming clematis have a single flowering season with no rebloom, setting flowers solely in early to mid spring. Flower buds form on shoots that only emerge from old wood (last year’s growth), so these varieties do not require any pruning prior to flowering lest you accidentally prune out wood that is about to host flowers.
As the new growth starts to emerge, it becomes clear how much of the vine died back during the winter and could therefore be thinned out, but it’s advised to wait until after flowering to groom out dead wood, remove tangled growth, and to reshape and resize. Under no circumstances should you prune these clematis varieties in the fall or early spring or you’ll probably prune off blooming wood, resulting in little or no flowers for the year. Spring bloomers rarely, if ever, set additional buds.
Spring blooming clematis varieties tend to be evergreen or most evergreen forms, so their application in a Utah landscape might be limited, especially compared to most of the other clematis that are comfortable down to Zone 4 conditions, provided they’ve been mulched over for the winter.
13 Favorite Spring-Flowering Clematis Varieties
- Apple Blossom
- Avalanche
- Blue Bird
- Freckles
- Maidwell Hall
- Mayleen
- Pamela Jackman
- Pink Swing
- Pixie
- Rubens
- Ruby
- White Swan
- Willy
GROUP 2: LATE SPRING & INTO SUMMER BLOOMERS
This type of clematis blooms heavily off of old wood (last year’s growth) and then, after adding a growth flush following this, sets a lighter bloom set on new growth. This second flush often waits until summer cools off, so it might be September before you see these blooms again.
This combination of old growth and new growth flowering means these vines require moderate, selective pruning a couple of times during the growing season. The first prune ought to happen early in the spring, just as new buds emerge and the stems tell you how far back they’ve died during the winter. Removing dead or damaged stems is the first priority, followed by identifying up to a third of the remaining stems that are then pruned down to obviously active buds about a foot from the ground. The rest of the vine is then left to start the first bloom cycle, this time off of old wood only.
A second prune immediately after this first wave of flowers is advised if you want to maximize the potential for a decent second bloom cycle set off of new wood. After the initial bloom is complete, deadhead thoroughly to help the vine invest in new growth instead of seed production, or simply cut the stems back to a healthy set of buds but with the resulting flush in mind. Just remember that this second prune is the last time you get to shape the vine or reduce its overall size; you want to avoid pruning again in the fall if you want to preserve the best flowering for the following year.
19 of the Best Summer Blooming Clematis
- Herbaceous, Non-Vining
- Arabella
- Mrs. Robert Brydon
- Sapphire Indigo
- Solitary
- Vining
- Aotearoa
- Avant Garde
- Ernest Markham
- Golden Tiara
- Hagley Hybrid
- Happy Purple Jack
- Jackmanii
- Pink Fantasy
- Pink Mink
- Princess Diana
- Ramona
- Rouge Cardinal
- Sweet Autumn
- Sweet Summer Love
- Ville de Lyon
GROUP 3: SUMMER INTO FALL BLOOMERS
This final clematis group features late blooming varieties that flower from midsummer through autumn, pushing blooms entirely off of new wood formed during the growing season. This means that they cannot bloom off of old wood, so hard pruning is required to eliminate winter killed stems and to allow the vine to best refresh itself and not develop an unmanageably tangled structure.
Group 3 clematis varieties are often considered the most straightforward for the average landscape gardener, as long as you don’t expect flowers until well into summer. As such, they can provide a welcome supply of stunning color during a time of year when the landscape is suffering from summer burn out.
17 Favorite Fall-Flowering Clematis Varieties
- Arabella
- Bijou
- Comtesse de Bouchaud
- Daniel Deronda
- Ernest Markham
- Fairydust
- Hanajima
- Happy Jack
- Henryi
- Ivan Olsson
- Madame Julia Correvon
- Piilu
- Princess Diana
- Rouge Cardinal
- Sweet Autumn
- Sweet Summer Love
- Taiga
Monrovia varieties
- Evergreen Armandii Clematis Group 1
- Apple Blossom Clematis Group 1
- Avalanche Evergreen Clematis Group 1
Boulevard Series: compact growers & containers
- Boulevard® Acropolis™ Clematis Group 2
- Boulevard® Cherokee™ Clematis Group 2
- Boulevard® Nubia™ Clematis Group 2
- Boulevard® Parisienne™ Clematis Group 2
- Boulevard® Sarah Elizabeth™ Clematis Group 2
- Boulevard® Olympia™ Clematis Group 3
- Boulevard® Sacha™ Clematis Group 3
- Boulevard® Tranquilité™ Clematis Group 3
- Boulevard® Samaritan Jo™ Clematis Group 3
- Boulevard® Poseidon™ Clematis Group 3
Vancouver Series: compact growers, spring & summer repeat
- Vancouver™ Danielle Clematis Group 2
- Vancouver™ Fragrant Star Clematis Group 2
- Vancouver™ Mystic Gem Clematis Group 2
- Vancouver™ Starry Nights Clematis Group 2
Jackmantii forms:
- Jackman Superba Clematis Group 3
- Jackman Clematis Group 3
- Reiman™ Clematis Group 3
- Ruutel Clematis Group 2
- Rahvarinne Clematis Group 3
- Silmakivi Clematis Group 3
- Kilian Donahue Clematis Group 2
- Pink Champagne Clematis Group 2
- Nelly Moser Clematis Group 2
- Niobe Clematis Group 2
- Belle of Taranaki Clematis Group 2
- Patricia Ann Fretwell™ Clematis Group 2
- Huvi™ Clematis Group 2
- Regal® Crystal Fountain™ Clematis Group 2
- Regal® Josephine Clematis Group 2
- Marie Louise Jensen™ Clematis Group 2
- Mrs. Yuki Clematis Group 2
- Suzy Mac Clematis Group 2
- Phyllis™ Clematis Group 2
- Maria Therese Clematis Group 2
- Ilka™ Clematis Group 2
- Hakuba Clematis Group 2
- Blue Light® Clematis Group 2
- Hania Clematis Group 2
- Julka Clematis Group 2
- Piilu® Clematis Group 2
- Multi-Blue Clematis Group 2
- Westerplatte Clematis Group 2
- F. Young Clematis Group 2
- Doctor Ruppel Clematis Group 2
- Royal Cascade™ Clematis Group 2
- Comtesse De Bouchaud Clematis Group 3
- Candida Clematis Group 2
- Blue Climador™ Clematis Group 2
- Shikoo Clematis Group 2
- Freda Anemone Clematis Group 2
- Pink Anemone Clematis Group 2
- Toki Clematis Group 3
- Sugar-Sweet™ Blue Clematis Group 3
- Sweet Autumn Clematis Group 3
- Ernest Markham Clematis Group 3
- Arabella Clematis Group 3
- Sapphire Indigo™ Clematis Group 3
- Rouge Cardinal Clematis Group 3
- Taiga Clematis Group 3
- Blue Ribbons Bush Clematis Group 3
- Princess Diana Clematis Group 3
- Ville de Lyon Clematis Group 3
In the surprisingly wide world of vines available to the northern Utah landscape, clematis merits its place as a reliable choice for unique flowers, bold colors, and a manageable size.
One last note about on Clematis: many new varieties have been introduced specifically for container gardening. This application can be successful in Utah, but special consideration must be given to effectively watering these containers in the summer (most likely using drip irrigation) and keeping the root mass from drying and freezing over the winter (the fate of many other attempts at overwintering containers).
