Poor Flowering on Mockorange
We purchased a Mockorange bush about five years ago and it has only had flowers on it two years ago - and then it was only two or three flowers.
Mockorange (Philadelphus), like lilacs and forsythia, bloom on old wood. Always prune spring blooming plants, right after flowering, if you want the flower display. Pruning at other times won’t hurt the plant, it just eliminates the flowers. Avoid excess nitrogen that can prevent flowering. Mockorange plants are hardy to zone 4 but their flower buds do not always survive colder Midwest winters. Select one of the flower bud hardy cultivars such as Minnesota Snowflake or Glacier for reliable bloom.