Pruning first year Vanilla Fraise Hydrangea?

artykst

I bought 2 9cm pots of the Vanilla Fraise Hydrangea and the 'dead sticks' duly arrived in the winter.  Having looked after them in the greenhouse and potted on etc they burst into life but have got rather long growth.  This growth is not too spindly but I have had to support it when potting on again today.  I cut one particularly long stem back and it is already sprouting more stems of course.  Wondering if it will hurt at this time of year to cut it back to create a bushier and hopefully more stable plant.  Assume I will not get flowers this year.  Stems are around 1'6" and not thick like my mop heads and Lacecaps

Elfer

Vanilla Fraise is a bit different to most Hydrangeas as it has an upright habit so as a mature plant it can grow to 2.4m in hight but only 1.5m spread. Most other Hydrangeas have equal height and spread.