BC,

I have read that one should go easy on the fertilizer for the climbers. Perhaps you have experienced a perfect example of why this is so. Climbers seem to bloom when they are darn good and ready and not a moment sooner. Since yours have bloomed in the past, is it possible that an unusually cold winter or an early spring frost could have affected them? I had the same thing happen on a Lilacina this year. All fertile and very few sterile. Maybe someone else will chime in with a theory on why this happens. Wish I could be of more help......yg

I don't know why this happens, but I noticed it this year on my 15-yr-old climbing hydrangea. It was hard pruned last year, had lots of flowers this year, but fewer sterile ones than in past years.