That's strange. Mine are still green here and it's hot. Are your plants in shade?

My plant would start to yellow here not long after bloom because it was planted in full sun. I've found it will die back/go dormant if planted in full sun or a dry location, but stay green longer if in a shaded site. ;-)
CMK

Mine is just finishing blooming, in almost full sun and is still green. It really doesn't start to yellow until late summer.

Kevin

Do you think it may be watering issues? Check for root rot. I have the fern-leafed bleeding heart and it blooms from April until frost. The common one will often go dormant in full sun.

Good Lord!! This plant hasn't been out of the ground that long. Winter is barely over. A little sun is NOT going to cause it to go dormant this early. Something else must be going on.

Kevin

I think I will give it a good drink of water today and see. I've never had issues with this plant in the 5 years it's been in the same spot. We've had a dry spring with major temp. fluctuations. - 80's in March and 40's in May. It's in dry sandy soil and I do water it, but maybe it needs more. It's in partial shade, but it's been there for several years. I might check to see if there is something going on with the stems that I can't see from the surface.

I actually bought 2 of these with yellow foliage called 'Gold Heart' this year. I wonder how you tell if they are sick. Hmmmm.