Why no berries on my Sorbus vilmorinii?

[loveverona]

I've had my gorgeous Sorbus vilmorinii for two years. The 1st year it hardly had any flowers and therefore very few berries. Last last year it flowered and berried prolifically. But again this year there are hardly any berries.

I haven't done anything different from one year to the next so can't understand why it would be so short on berries again after such a good year last year. Could it be something to do with the severe winter we had last year?

Any thoughts?
Thanks

Does it get enough sun where it is? That could be the reason for the flowers shortage.
Rowans like plenty of sun, idelly not shaded by anything else.

Yep, plenty. And it had loads of flowers and berries the year before last, so can't understand what's happened this year.

Anyone else...???