clematis

When do you want them to flower?

Vyvyan Pennell is an early summer one - she also flowers again in late summer. She is a double purple with a large flower. If you choose a Clematis viticella, maybe 'Etoile Violette', that flowers in late summer and will continue the flowering season for you.

You can also go for any of the alipina or macropetala species which are nice and early before moving onto mid season and then late. I would agree on 'Etoile Violette' for a late flowerer - it's a gorgeous one.

I have C. amandii now followed by C.montana Elizabeth in one shrub.early-late spring
macropetala followed by jackmannii in another, spring/summer
Victoria through a climbing rose new dawn ,followed by seiboldi.
C tanguta[spelling?] lemon peel through a yew and
ladybird johnson through dwarf conifers. both late summer.
the choice is endless. they are an excellent group of pplants.