How do I care for bleeding hearts the leaves are turning yellow and falling off?

What time of year is it? My bleeding hearts (Dicentra) naturally go dormant in hot, dry Chicago summers. Plant hostas or daylilies nearby to fill in the empty spaces they leave. If you believe the plant is dying too early in the season, my first thought is that the soil is deficient in nitrogen. Only a soil analysis will tell you for sure, and it is a good idea to have your soil tested anyway. If other plants nearby seem to be suffering as well, you could be over-watering. Bleeding hearts are one of the few plants to do well in full shade, but that doesn't mean they like wet feet.