I'm surprised I must say that you have new shoots that have been caught now??? This is a question I would normally expect in April.

If it has produced new growth that has been frosted, it will be only a temporary setback. Buds just below the soft growth will shoot in spring.

Yes, I know - it's in a sunny corner and has produced lots of new growth - the trouble is - I live in a cold, windswept almost moorland area and we had a rather severe frost last week - so who knows how the pieris will go on - it's the first year, it's in a very large pot against a south facing wall - so we'll see! Thank you very much for your reply

If it was me, I would wait until spring to cut out the frosted parts. Most of your cohorts there in the UK have also been advising people to bubble-wrap their pots to keep the soil from freezing.

Thank you Tugbrethil
I will wait until spring, not least because there will be much more frost to come. I posted the question because I read something recently advising cutting out frost damage immediately - think the person must live in the south of France! We've been to Arizona - what a wonderful place - could hardly be more different from NE Lancashire! (also wonderful of course) Regards