We planted five plants 3-5 years ago. The three on the left are large and bountiful and the 2 on the right are on the puny side. The yard faces East and get sun until approximately 3 PM.The soil is clay/sandy and usually dry.
We prune the plants in the Spring.

Is there anything a remedy?


Thank you for contacting Toronto Master Gardeners to inquire about your Hydrangea plant.  Your hydrangea plants have so many beautiful blooms!  From your photo, it seems two hydrangeas closer to the house do better than the other two closer to the sidewalk. Notice that the grass closer to the house also does better. The plants closer to the house seem to benefit from having more shade. The soil appears fairly dry. How often do you water these plants? Hydrangea plants require sun to maximize blooms, but they also need well-draining soil and plenty of water.  We’ve had some very hot, dry days in June.  Hydrangeas need consistently moist soil and don’t do well when the soil dries out. 

It is also possible that the hydrangea closer to the sidewalk suffered from salt injury during the winter when salted snow melted.

The Halton Master Gardeners have written a gardening guide  https://haltonmastergardeners.files.wordpress.com/2020/08/hydrangeas.pdf to growing hydrangeas with information on fertilizing, winter protection and pruning and a reference table with information about different types of hydrangeas commonly found at nurseries. It also lists the most common varieties and whether they bloom on old or new wood.