The Horticultural Society has some wonderful pocket-sized books on clematis, I thought I would share some of their info. I bought this 10 years ago, so the names are from what was available then. I'll post for each group. I hope your lovely vines benefit from the info. I learn something new each time I pick up the book and apply it to one of my pretties.

Pruning Group 1

Flowers on the Previous Year's Wood. Dense Growth.

1 Cut stems back to a pair of buds or to the point of origin.

2 Cut back any weak or damaged growth to strong buds or to its base.

Not essential to prune, but thinning can invigorate.

Montanas dislike hard pruning into old wood, can cut away twiggy old but always leave some strong stems.

LIST

Clematis alpina

Columbine - Constance - Frances Rivis - Frankie

Helsingborg - Pink Flamingo - Rosy Pagoda - Ruby

Subsp. sibrica

White Moth - Tage Lundell - Willy

Clematis armandii

Apple Blossum - Snowdrift

Clematis x carmanii

Joe

Clematis chrysocoma

Clematis cirrhosa

var. balearica

Freckles - Wisley Cream

Clematis gracilifolia

Clematis indivisa

Cleamtis koreana

f. lutea

Clematis macropetala

Blue Bird - Jan Lindmark - Lagoon (Blue Lagoon)

Maidwell Hall - Markham's Pink

Clematis montana

Broughton Star - Elizabeth - Fragrant Spring - Freda

f. grandiflora

Marjorie - Mayleen - Picton's Variety

var. rubens

var. sericea

Tetrarose - Warwickshire Rose

var. wilsonii

Pruinina - Rosie O'Grady - White Swan

next post contains Pruning Group 2

I haven't seen half these listed, if you have pics, would love to see them.