loss of color in zinnias

[jj]

Why do my zinnias lose their vibrant color after planted? This is Phoenix, AZ. Some of these plants are in direct sunlight while others are in partial shade. I planted them with a good depth of Miracle Grow potting soil but in the ground. I have fed them about every ten days. They get watered once a day about four A. M. BTW, I have the same problem with daisies. Other flowers, herbs, vines and all the annuals do extremely well. I get deep purples and vibrant yellows.

[scottishbelle]

[Sparky Organic]

My zinnias bleach out too, after a while - I think it's just a natural phenomenon.

BTW I wouldn't feed annuals as much as you say you do. The trick with annuals is to keep them anxious to flower as much as they can, so I keep my soil as lean as possible.