There may be many reasons, not necessarily sun related. I have had some that do not bloom on year one and assumed they were working on getting their root systems developed.

Paniculatas are probably the most sun tolerant of hydrangeas but the leaves/blooms will suffer if exposed to afternoon sun in warm zones like mine. I recommend giving them morning sun only, dappled sun or bright shade. But in bright shade, the lime green will last longer, sometimes the length of the whole growing season and thus, you may not get a white color. So, the more sun, yes, the better but try to keep it to morning sun as much as possible. Again, since you have disturbed the roots again, it may skip blooming on year 1 in the new location if it is trying to develop a good root system.

I would wait 3 years for any hydrangea to become established. If no blooms by then it is probably a no-go. Just two other things: Do not prune it in the Spring or Summer and make sure you do not have deer or squirrels that may be eating the flower buds. I can get blooms quite early -early May for example- so better to leave any pruning to winter or late Fall in the rare case you would ever need to prune.

Your zone has very little (actually nothing) to do with how well this plant may do in your climate. Hardiness zones only reflect the average minimum winter cold a plant can tolerate - nothing more. Why growers insist on applying these in a range to various plants makes no logical sense and just confuses consumers........if it will survive winter in a colder zone, obviously it will survive winter in a higher/warmer zone!!

I am in an equally mild zone and all manner of hydrangeas grow like weeds here. But we do not experience high summer heat nor much in the way of any humidity. And those issues could be a factor in how well a plant may thrive and influence its siting. Luis is much better able to address those issues for your location but I doubt they pose much of a concern for a paniculata.

Guess I may be late posting on this subject. I am in Houston zone 9. My advice is to not even try paniculata types of hydrangeas. I have tried them in 2 different areas of my garden. They just don't bloom or for that matter, they don't grow. I believe the tags on these say zone 8. I tried, hope you get this post. Carol in Houston

" I believe the tags on these say zone 8. "

Once again......the hardiness zones ONLY reflect a plant's ability to survive winter cold temperatures. They have nothing to do with summer heat and humidity or lack of it, so do not make decisions about climate suitability based on that factor. You may have to make adjustments for your climate with regards to siting (more shade than sun) and sufficient water, but there is no other reason these plants won't grow in southern gardens. Perhaps this publication from MSU on hydrangeas suitable for MS gardens will help

btw, Hydrangea paniculata varieties also come highly recommended by TAMU and other Texas sources, coming in right be behind oakleafs for suitability in east and south TX gardens. What they say are much harder to establish and grow are the macs.

Carol, Give 'em another try. See excellent link to Hydrangea publication that gardengal48 provided above. I transplanted my paniculata to a spot where it receives more sunlight...I think I had it in a spot that was to shady. Yes, the tag does indicate zones 3-8. Was your paniculata planted in enough sun?..too much?