They’re being bleached by the UV rays of the sunlight. Usually the reddish hues fade fastest because they absorb those shorter wavelengths.

I wanted to come in with some silly, snide remark – because this is Social and I can – but @thorninmud‘s calm, sensible answer has taken the wind out of my snarky sails. Drat it!

You could try a little high potassium fertilizer, like a tomato or flowering plant mix. It sounds a little early for them to be past peak but I’m not used to your weather. Stay away from the high nitrogen fertilizer.

It also signals the end of their prolific blossoming, which they do for a limited time, being a perennial.

Min are only just starting to rush out of the ground. But you live in much balmier climes.

My flowering fruit trees (and those in town) were glorious for less-than-aweek. Now there is a shower of petals and a carpet on the ground.

Make sure you watch for the seed pods to dry out. Harvest and save for next year.