Have you pruned it at the wrong time?, these can be hard pruned and always come back looking fine, however I always trim back prunus incisa carefully so as not to spoil its natural growth habit this I always do towards the end of April depending on the weather, have you pruned it in the autumn?.

has it got overly wet and been standing in water for a prolonged period of time? If it has that could be partly the problem as it wouldn't get enough oxygen to help transport nutrient up to the developing buds.

Would water logging be a problem? I ask has I look after this chaps garden who has two large shrubberies, in these borders are a large prunus incisa, exochorda the bride, euonymus alatus, amongst others these have had their feet submerged in water for such along time due to all the winter rain, the prunus is flowering cheerfully and the exochorda is straining at the bit to burst into bloom.

Stera's is quite small so would be more susceptible I think. It was a possible solution but it may not be the real reason.
was it given a good feed last year?

How disappointing Sue . . . does it get enough sunshine?

Thank you everybody!

Julien - I didn't prune it at all...Should I have done?

I don't think it was waterlogged as its at the top of a slight slope, but its been so very wet this winter that who knows...perhaps that was the reason then.
I just looked up its height at maturity (should have done that before I was seduced by one at Tesco in full flower...) I didn't realise it grew to 6 feet

I have never fed it - tend to leave trees to look after themselves. Oh dear I sound like a rotten gardener...

Sheila - yes it gets full sun most of the day. I planted it where it is to give some shade to the pond in the heat of the day.

So possibly all I can do is feed it - when is the best time?

I lost mine this year, Stera. It died but still felt firmly rooted. When I turned it out, however, I found vine weevil grubs in the roots.

add slow release fertilizer to the soil when the leaves start to open. Is it in grass or does it have a soil 'bed' around it? if in grass its harder to feed if you have bare soil just rake it in.

Thank you Eileen. No it isn't in grass and there's nothing much underneath it. I think it will have to be Growmore because I'm out of slow release and the shops are closed...

Pennyfarthing - so sorry to hear about yours - dratted vine weevils have a lot to answer for don't they?

Sbg I forgot to tell you that it has now been fed and gently raked in.A few more flowers have appeared among the leaves though they hardly show - it seems to have got confused about when to flower. So fingers crossed for next year - that's what gardening's like isn't it...