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Clematis are available in all shapes, sizes and colours – they can either be climbers or herbaceous (non – climbers), and their spread and height can vary significantly. There are literally hundreds of different varieties that are available.
Last year I bought a clematis “Miss Bateman”, which is a compact climber. I was hoping to grow it in a pot on my patio so that it would cover my bare wooden trellis with thick foliage and abundant flowers. But this isn’t quite how things have worked out and, as you can see from the picture above, my clematis is not thriving. This year, it has only so far produced a single stem. I have had just 2 or 3 flowers between mid April and mid May. Not good!
It is currently growing in a pot that I suspect to be way too small, so the first thing I am going to do to try and revive its fortunes is to repot it into something larger.
Clematis should be repotted every 2 to 3 years. The best time to repot is in the spring or early summer. Clematis should be repotted into a pot at least 18 inches deep using fresh, free draining, soil based compost.
Which varieties of clematis are best for growing in pots?
Clematis have deep root systems that typically extend down to a depth of around 60cm.
If you do want to grow clematis in a container as a climber, it is a good idea to pick one of the early flowering compact types as they are best suited to this.
The variety that I am growing, “Miss Bateman”, is a hardy (down to around -15 degrees) compact clematis that initially produces large, white flowers in late spring and early summer – often with another flowering later on in the summer as well! It should reach an eventual size of around around 0.5 to 1 metre wide with a height of around 2 to 2.5 metres and is ideal for growing in containers.
Other varieties of clematis suited to container growing include clematis “Carnaby” (purple and white flowers) and clematis “Niobe” (ruby red coloured flowers). Check out these varieties of clematis suitable for growing in containers on Amazon below!
Repotting my clematis – removing the old pot
There was only one sure way to find out exactly what was happening with the root system of my clematis and that was to remove the existing pot. Once loosened off, I pulled the pot free from the plant and found that it was somewhat pot bound.
Clematis have relatively deep, tuberous roots that extract the required nutrients and water from the soil, and these roots had run out of space. Not good news as a restricted root system alone can be enough to severely stunt growth.
On the plus side, apart from being pot bound, the roots on my clematis looked relatively healthy. Healthy clematis roots should be orange in colour and should be flexible, which mine were. Prior to repotting, while trying to keep disruption of the root system to a minimum, I removed of as much of the old and loose soil as I could.
Choosing a new pot for your clematis
When deciding on a replacement pot for your clematis, you will need to take into account it’s size, material and drainage properties.
As already mentioned, clematis have deep root systems. The original pot I had was way too small. As a general rule, clematis need a pot that is around 18 inches deep to grow into.
My original pot was plastic, which was not ideal.
Clematis roots need to be kept as cool as possible and hot soil will negatively affect the growth of the plant. Plastic pots tend to retain and hold in heat as they are not breathable.
Terracotta pots on the other hand are much better when it comes to breathability and they tend to retain much less heat. So terracotta is a much better option of pot when it comes to keeping the root system as cool as possible.
Another good alternative is wood. Wooden pots are good for keeping roots cool as they are also breathable.
Clematis do not do well in waterlogged conditions so it is important to ensure that whichever pot you use has adequate drainage holes. Adding some crocks at bottom of a pot can also help drainage.
This is the pot that I chose
So, after careful consideration, this is the pot that I chose (below, right). It is terracotta – a lot larger than the previous pot – with a good, large, drainage hole at the bottom.
Which compost is best for clematis?
A soil based compost, such as John Innes number 2, is ideal as it contains high nutrient levels along with sand and grit which helps drainage. You can improve drainage even further by mixing in some additional grit, or perlite, (around 25%) with the compost (around 75%).
Follow the links to shop for John Innes number 2 compost and perlite on Amazon below:
My repotted clematis
I repotted my clematis using John Innes no2 compost. When repotting, the root ball should be completely covered with compost.
To help ensure good drainage, I used some pot feet to raise the pot slightly off the ground. Pot feet allow you to easily and evenly raise the pot and the feet that I used are not really noticeable when in place. The gap that they create is a great help when it comes to preventing the drainage holes at the bottom of the pot from becoming blocked:
The pot feet that I used are available on Amazon below. I only used 3 pot feet in total. You can vary the height of the pot by using more or less pot feet, depending on your requirements.
Clematis pruning and pruning groups
Clematis should be pruned annually. They are split into three separate pruning groups depending on when they flower: group 1, group 2 and group 3. You will need to check which group your specific clematis is in as this will determine how it should be pruned:
Group 1 Clematis flower in winter and early spring on the previous year’s growth
Group 2 Clematis flower in spring and summer (on new and old wood). Also known as “twice flowering”, clematis in group 2 will often flower again in late summer around August to September.
Group 3 Clematis flower in late summer and autumn, on the current year’s growth
The Clematis that I have, “Miss Bateman”, is in group 2 so should flower in spring and summer (from March through to June in the UK) and possibly again from around early August to late September.
Group 2 clematis should be pruned regularly as this will stimulate thicker growth. The best time to prune group 2 clematis is either early spring (before flowering) or after the first flowering of the year.
Pruning my young “group 2” clematis
My clematis is a young plant and so far has produced just a single stem of growth. As the first flowering is now over, it is time to prune.
To encourage branching and the growth of multiple stems in relatively young, group 2, clematis such as mine it is best to cut the single main stem right back down to just above some good, strong leaf buds. This is what I have done: I cut back to around 20cm above the base of the plant.
All being well, over the summer I should now see more stems start to develop and grow. By training these new stems across the trellis I hope to be able to achieve a good overall coverage and give the plant some structure.
Pruning an already established “group 2” clematis
If you have an older, already established, group 2 clematis, any pruning completed should be as light a possible so as to maximise the amount of flowers and maintain the current structure of the plant. Before any growth occurs, in early spring, clear any dead wood or weak stems and prune down to just above the next healthy buds, keeping as much of the plant structure intact as possible. This will encourage strong new growth in the coming year.
What is the best position for a clematis?
This will depend upon the type of clematis you have. It is best to check for your individual clematis but most prefer to be sited in a sheltered location that enjoys either full sun or partial shade, and this will generally promote strong flowering. My clematis is grown in a part – sunny position next to a fairly well sheltered wall.
Keeping the roots cool
To try and keep the roots as cool as possible, I have used some slate chippings around the plant base which will give the soil some shade and protection from the heat of the sun.
Keeping the roots cool when growing in pots can be a challenge as the upper parts of most clematis need to be positioned in full or partial sun to thrive.
Looking after clematis in pots
So now my clematis has been repotted and pruned, I just need to look after it and wait for new growth.
– How often should a clematis be fed?
Clematis will need ongoing feeding and I am using miracle grow general purpose feed about once every 2 weeks during the summer months (always follow instructions on label!).
– How often should a clematis be watered?
Climbing clematis need to be well watered and their roots kept moist (but not waterlogged). The deeper, more nutrient rich, and better draining the soil, the better the clematis will do. As a rough guide you will need to water your group 2 clematis around twice a week during the summer months, right up until the plant starts to die back in winter.
– Protecting against garden pests
Watch out for slugs and snails! I have had some issues with leaf damage from slugs and snails – I have been removing the slugs and snails by hand to overcome this problem, which seems to be working. Check out our article on the 7 top ways to keep slugs under control in your garden!
Check back later for updates!
Hopefully you now have more information on how to repot and revive your clematis!
Be sure to check back later in the year for updates and find out how my clematis fared!