I think its all the rain we have had , is the plant in well drained soil ?

Gg

Did you plant it deeply enough? Try heaping some soil gently round the base and see if it makes a difference next year.

When you say it buds every year, do you mean flower buds, and if so, what happens to them?

Do you mean that it has failed to flower ever year for 10 years?

Are they receiving enough sun? They do like a sunny position and moist soil. So if they are not getting enough sun the buds may fail to open.