Hydrangeas: Overwintering macrophylla?, 0 by CapeCodGardener

CapeCodGardener wrote:
Hi! I have two florists' hydrangeas, which I purchased as houseplants in March 2006. They've been inside in a gently sunny window ever since, kept moist and lightly fertilized. Now the flower heads on both are green--but no leaf drop as yet. What should I do to overwinter them? Presumably it's too late to plant them outside in my climate (zone 7a.) . I'm just not sure what to do at this point. I have a grow-light set up in the basement, and could move them there. . . will they eventually move into Fall status, as my outside oakleaf and PeeGee hydrangeas have already done?

As you can tell, I'm a hydrangea novice, who is depending on the kindness of strangers. I have heard that florists' hydrangeas can be more trouble than they're worth to overwinter. . .but I'm loath to let these friends go.

Thank you,

Emily