Coastal Maine wins. I was there last week with The Husband visiting my sister and my brother in law and oh what a beautiful garden. Here is how the website describes the garden:
Coastal Maine Botanical Gardens is a people’s garden, a grassroots effort that began as a casual conversation between friends and evolved into the largest botanical garden in New England. Located on more than 300 acres along the MidCoast, the Gardens is a true Maine experience.
If you find yourself anywhere near Boothbay Harbor next summer you should check it out. They are closing soon for the season but there will be a holiday light show.
For more info: https://www.mainegardens.org/