Hi, I had 5 Limelight Hydrangeas planted by a landscaping company this past spring. They have grown tall but haven’t bloomed yet. The stems are at least 4 foot tall and look healthy. I have searched for answers about what to do before Fall Winter. Do I prune them? And if so, how far down.Any advice would be greatly appreciated!!! Thank you, Michael
The Panicle Hydrangea will flower on current year's growth. This has me thinking that it is, simply, not established enough to bloom. Likely, you will have blooms next year. These articles will help with Hydrangea care.
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/care-of-peegee-hydrangea-plants.htm
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea
some black spots. They also have recently bloomed, I don’t know if they’re yellow from the season or if I’m over, or under watering, please help!
Unfortunately, your photos did not come through. I am unable to see, exactly, what the symptoms are. I can assume that the cool weather has taken hold of your shrubs, and I am seeing the same thing in my area. This is a normal process before colder weather. These articles will help you with your shrub:
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/tree-hydrangea-growing.htm
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea