|I have 3 blue-flowering corydalis, planted this May, in a bed with astilbe, brise d'anjou polemonium, and hosta (all these doing very well in second year), shaded by a styrax obassia. One of the corydalis appears to be dying and the other two are showing yellow outlines on their leaves. I don't think watering is the problem and I can't see any pests - do these plants suffer from viral or fungal diseases or might something be devouring the roots? These were not cheap little plants, so I'd really like to save them if possible.
|Unfortunately, corydalis can be difficult to grow outside the Pacific Northwest and other cool summer areas. Some varieties go dormant during the summer, when the weather turns hot and humid and that might be what yours are beginning to do.