Posted: 24/06/2015 at 12:11
Climbing plants that flower over long periods need a great deal of nourishment and watering and I personally feel it's a bit much to ask of a rose or clematis to thirve, year after year, in the same pot of compost unless you can guarantee that you can feed and water adequately.
I suggest you have a play with annual climbers. There's a colourful range to grow from seed or from plugs and small plants available from garden centre. Most are not hardy so need to be grown on till all fear of frosts is over. Have a look at the info here - https://www.rhs.org.uk/Advice/Profile?PID=590
If you really do want permanent plants, have a look at repeat flowering ramblers such as Malvern Hills (pale yellow) or Snow Goose (white) which have good perfume, Narrow Water (pale pink), Phyllis Bide (pink) and Rambling Rosie (pinky red), Red New Dawn, Super Dorothy (deep pink) and Super Elfin and Super Excelsa - both red.
Ramblers can be trained over arches more easily that climbers and all of the above will flower through the summer if kept well fed and watered. They will need the best compost you can buy such as John Innes no 3 mixed with a bit of multi purpose for water retention and an annual spring feed of slow release rose fertiliser plus weekly liquid feeds of tomato food or comfrey tea form April to late June. Feeding later than this produces soft growth which doesn't have time to harden off before winter frosts. Keep on removing the spent flowers to stop them spending energy on hips and encourage more flowers.