Pruning roses and clematis with new growth

Dedekind

Hello,

due to various building works I have not been able to do much in the garden, now it's clear and I was going out to start pruning Group 3 Clematis and some Roses,  but I see that all of them have new growth! I'm based in London.

Is it too late to prune? Should I be cold-hearted and just do it? I am afraid of losing some of the growth for the year.

Fairygirl

No , just prune as normal. 
I'm talking about the clematis - I don't grow roses. 

Dedekind

Thanks. I went out and did it but very mildly.. it was a new Clematis planted last year so it felt weird cutting it back hard. I removed all dead bits and cut off everything up to whenever new growth was. Overall the longest shoot left I think is about 3 foot.

Fairygirl

It's how Group 3s are pruned though - back to around a foot is ideal each year. It won't harm it if the stems are longer, but ideally, you want the flowers low enough to appreciate them, rather than on long stems at height.
You can always train the longer shoots sideways if you don't want to cut them back further 
They will produce new shoots from below soil level too, which is why it's recommended to plant them slightly deeper than they are in the pot. A young plant also takes several years to reach maturity and give full coverage. Most suppliers don't send out plants that are younger than couple of years. If you bought it one of the supermarkets or similar, they're younger. 

newbie77

You can prune roses now. I just finished some today. 

Busy-Lizzie

Not too late for roses. It will encourage them to make new growth.