In 2007 I planted a philadelphus Sadly the wrong one as it is the large variety. It struggled the first couple of years then did better then 'helpful hubby' pruned it right back in the spring - "beca\use it looked straggley" So it struggled again for another two years. Last year was looking good so I was hopeful of flowers. It is about 8' - 10' tall !! BUT only one flower spray. It is still looking very good but I have told it - if no flowers next May/June it is for the tip. What is going wrong please gang ?