Baby clematis: Plant out or mature in pot and a few other questions

Chickpea78

Hello everybody, I am new to gardening and this is my very first question on this forum. My situation: Around 2-3 weeks ago (can’t remember) I bought two baby clematis in 9 cm pots (Nelly Moser, Group 2, Comtesse de Bouchard, Group 3) and had already dug out one spot for one of them thinking they should be planted out as soon as possible. Then I came across advice that it is better to keep them in a pot for one season (or maybe more?) to let them mature and develop a good root system first. This made complete sense to me so I put both of them both in their own pot planning to cut them down to 30 cm (?) in the end of February next year and then plant them out in the garden. My dilemma now is that they have already grown to over a metre and I don’t know how to support them in the pot till spring at this rate. I know I should have some kind of trellis but all I can find online are obelisks which are too wide on the bottom and don’t fit in the pot so at the moment they are growing straight up on the canes but at this speed they reach the sky soon...Am I not able to prune them back at all before spring? Would I need to bring them inside coming winter or would they survive outside (Maybe trying to insulate the pots with a sleeve)? We have a narrow but tall unused trellis fixed on the wall of the house (west facing) but if I let them go wild on that one I would not be able to move the pots anymore in case of frost. I am panicking a bit and toying now with the idea of getting them into the ground as soon as possible but doubt I get them out of their pots without causing a lot of damage to them as they are now wrapped around the canes and look incredibly fragile. Any suggestions are gratefully received!

Chickpea78

I will try to post photos. The turquoise pot is Nelly Moser and the brown pot Comtesse de Bouchard. They are both inside at the moment as it is stormy outside.

Chickpea78

Apologies for the state of the house and patio. We just bought the house and it is a big project ;-). As is the garden which is so exciting!!

Fairygirl

Please put them back outside. Just somewhere sheltered, and not in strong sun
If you keep coddling them it won't do them any good. They're both very tough plants
Keep them potted, and you can probably plant them out in a couple of months.
I'd have cut them both back to encourage more stems. It makes for better, stronger plants next year, and encourages new growth from below.  You can just use a couple of canes and soft string round those to give them support.
Make sure they're up off the ground too - if you don't have pot feet, just use bits of timber or bricks  - anything really. 

Chickpea78

Hi Fairygirl, thanks for the advice. I put them back outside in a sheltered spot as you said, it makes sense for them to toughen it out with the elements. I am relieved that you suggest to cut them both back as I had the feeling that them being so leggy can’t be good and will do that. Can you give me an idea how far to cut them down? If they grow tall again is it ok to keep pruning them down to a certain height or will that cause stress. I will get them of the ground and am curious what the reason behind that is? Finally, just to confirm planted them out in two month (June) will be ok and it doesn’t have to be in Spring or Autumn as so often mentioned? Thanks again for your guidance!

Fairygirl

Ok - clematis are very hardy - those two you have certainly are, so don't worry about them 
I'd prune them back to a good pair of leaf joints - maybe about a foot off them. That will make it easier for you to keep them tidy just now. I think you'll find that in another months or so they can go out in the ground. They look nice and healthy. It's also good practice to plant them a little deeper than they are in the pots. It helps develop more stems from below ground. Slightly different from most plants 
You can plant anything in a pot at any time of year, unless ground is frozen or waterlogged. I don't know where you're planting them, but take the time to get supports in for them - whether that's trellis, or wires and vine eyes. It'll save you having to faff around later. If you're putting them on fences or walls, rather than obelisks etc, don't plant them right against the wall/fence. Keep them about a foot to 18 inches away, and lean the supports you have [canes etc] towards the supports. The areas round the base of walls/fences can be very dry, which many clematis dislike. 
Nelly likes a shadier spot, so if you have an east to north facing spot, that will be ideal. It gets very faded in sun. The other one is happy in most aspects if I remember correctly, but here's a link to a site which will give you info.
http://clematisontheweb.org/index.cfm

You can also look at the specialist sites - Taylor's Clematis, Thorncroft and Hawthornes, who all specialise in clematis. Loads of good info on them

The reason for raising the pots off the ground is just to ensure drainage, especially on hard surfaces. It's equally as important as them getting enough water 

Chickpea78

Thanks for all the information. Yes, I read to plant clematis ca. 6 cm deep. I wasn’t sure if that applies to baby clems as well as the lower stem is not woody yet so will do definitely do this next time when planting them out. Would I remove the leaves which are on the very bottom or just bury them? I will make sure to have my support system in place. I chose the Nelly especially to go in a shadier spot so hopefully it works out 🙂.  Thanks for the specialist websites! Very grateful you are sharing your knowledge with me. That is so helpful. I know I only spent a few pounds on them but I am trying to do my homework to give them a good start. 🙂

Fairygirl

I wouldn't worry too much about the bottom leaves, but you can remove them if you want. You'll find the stems toughen up quite quickly.
Alternatively, you can plant at the same level, and add some extra compost around the base every so often. 
They can be very addictive - it's probably a bad idea to look at the sites too often 

Chickpea78

Thanks, Fairygirl.