Hydrangeas: Diagnosis please...Disease, Stress, Sunburn...What???, 0 by yotedog

yotedog wrote:
This is a lovely Shooting Star (aka Fuji Waterfall) hydrangea that I received this summer. Yes, it was a forced bloom florist plant, but I cut it back, repotted it and it grew nicely on a shaded porch from mid summer till October. Brought it in the house about a month ago prior to any cold weather below about 55 degrees. Now it's leaves look like this, though the plant itself seems pretty healthy and is putting out new growth. It is in a South facing window where it does receive some direct sun for about an hour each day, and bright light the rest of the time. The spots developed fairly quickly (over a week or two) and are present on leaves on all parts of the plant, with the exception of those just coming out. No difference between leaves near the soil and those near the top of the plant--some of all are affected. Any ideas? My only thought is maybe sunburn as the plant had never had direct sun, and maybe even a short period of direct winter sun was too strong? No other plant is affected (this is the only hydrangea overwintering in the house--others are geraniums and coleus). Help--I love this plant!