Clematis flowering problems

Hi Everyone.  This is my first posting on the site. I have two group 3 clematis which are growing in pots; I bought them about 18 months ago.  I have cut them back in Feb to around 12 inches but when I planted them I didn't plant them deeply so I'm afraid that's the reason I'm only getting flowers at the top of the plant.  I'm planning on repotting them this year; does anyone know whether I can plant them deeply now, or can this only be done to new plants? Thanks for your help

I ave read that when you cut them back you should cut stems at differnet levels to get flowers all the way up. They should be plated with at least 3ins of soil on top so I guess as you are re=planting them you could do that. Secret is to plant as deep as you can if in a pot.

Some group 3 do grow and flower this way and there's not much you can do.  Having the pot in full sun will help, as will feeding with a low nitrogen, high potash fertiliser and pruning any really vigourous shoots to a pair of leaves during the growing season (which will keep it from growing too tall.)  I have a viticella 'blue belle' which doesn't get much direct sun until later in the season and that never flowers below 2m even though it is cut nearly to the ground each year.  All the other group 3s I have (dozens of 'em) usually produce flower from 1m upwards.  As Rosa said, you can try not cutting back some of the stems so hard in early spring, if they are showing live buds.  These buds may then produce flowers earlier in the year.  Most large-flowering clematis can be grown as group 2 or 3, depending on how you prune them.  The pruning groups 2 & 3 aren't set in stone and are only given as a guide to how each cultivar is 'normally' grown.  This became clear to me years ago when I kept finding the same cultivars classified differently, depending on which book I looked in, and that knowledge has helped to get the best out of my collection.

Does it get more light in the greenhouse than in the garden - or - are you not recognising the flowering shoots and pruning them all off and turning them into cuttings 

Leigh, you can plant them more deeply when you repot them. They really do need it to help prevent clematis wilt and to keep the roots cooler. As they are in pots have they been fed and watered enough? I find mine in pots need a really good soak every 2 or 3 days, rather than little and often.  Like the garden ones prefer a weekly soak, when the weather is dry. 

Not just yet, they will have the new compost. They will need it as the new growth starts. It's still winter.

I have two bowl shaped pots about 45cm dia in each are 3 Clematis of different types. When I planted these I had no idea what I was doing, totally green. 4 years on and a prune down each year up they come. I have a 2m obelisk's on each and start to wind them from the base up when they start to sprout, I can get only a few flowers to come out at the base, all start at the 1+m height. My other Clematis (43 last count) all start flowering from 1+m height.

I use the space at the base now to grow other plants.

Leigh2, do you know which 2 clematis you have ?  Are they viticellas, texensis, herbaceous, species or what ?  Most of these are summer flowering, group 3, but their growing requirements are very different, some need to be planted deep, others don't.  There are some  compact forms of summer clematis ideal for pots including some very gardenworthy Estonian cultivars, they are Late Large Flowered Group.

Hi Richard. I'm afraid I don't know whether they are herbaceous etc. I do know that one is called Josephine and they both have large double blooms

It is natural for clematis to flower at the top and the way to prevent this is to spread the stems sideways. The same is true of roses. The trouble with spreading clematis stems is that they ae very fragile and can get damaged even when you think you have been very gentle with them. That stem will then die back.You have to be very gentle and do it every time the plant makes a few inches of growth. If you have them in a pot with a pyramid support, an option is to plant more than one and gently take all the stems of each plant diagonally around the support. One thing that dawned on me when I looked at gorgeous displays of clematis in pots in garden shows was that there was more than one plant in there. Call me thick, but it took ages to realise this.

If they have large double flowers and one is Josephine, then they are not group 3 clematis.

Joesephine is a group 2 which means she should have a light prune immediately after the first flush of flowers in May and June to remove dead heads and any unwanted or old stems.  It should then be given a good dollop of slow release clematis food or blood fish and bone and a liquid boost of rose or tomato food.   This is particularly important for plants in pots with limited resources.   Given this encouragement, she should produce a secon flush of flowers at the end of summer but they will probably be less double.

Josephine is also known to be an unreliable flowerer if grown in poor conditions and may even produce greenish flowers if there isn't enough sunlight available.

Thanks Gardening Grandma, Richard and obelixx.  When I bought them I was told they were a group 3, so I probably pruned them wrongly as well which won't have helped.  I will give them some TLC this year and keep my fingers crossed but everyone's comments have been really helpful. Thanks