I love to photograph flowers and I have a yard full of gardens so that I don't have to go far to find good subjects. But one of the problems that I often face in photographing flowers (especially light-colored flowers) and that you've probably encountered, is that bright sun tends to burn out the highlights and wash out the colors.
The solution to this problem is one that most professional garden photographers use all the time: work on cloudy days. On overcast days the gentle light quality tends to saturate colors and lowers contrast enough so that you can good a good exposure without the risk of blowing away the highlights and very light tones.
I actually photographed this peony (I wish you could smell it!) blossom just as it started to rain (if you look very close you'll see some raindrops). I had come home from errands and saw the blossom fully opened and knew that once the hard rain started the blossom would fall apart. So, tired as I was, I hauled out the tripod and camera and shot this close-up. I was very pleased with the saturation of the pink tones and the way the soft light quality held detail in even the most delicate tones.
Cloudy days are great for all kinds of subjects, including outdoor portraits, so don't despair if the sun doesn't come out or if clouds pass by, the lighting is just beautiful!