I'm not an expert on lilies, but I always heard that lily bulbs need a reasonable amount of water during their active growing phases, as they are preparing to bloom and while they are blooming. But even after they are done blooming, I don't think they like roasting.

All I can say is that most of my lilies are in my rose bed and get watered by sprinkler any time I water the roses that way (occasionally I water the roses by hand--but usually by sprinkler). However, I have one cluster of orientals in another bed that often gets overlooked. Only in that last bed did my lilies exhibit the problem you describe, so I'm guessing we both need to water with a bit more regularity.

The other possibility is that your lilies have reached the end of their blooming cycles. Mine were mostly done several weeks ago, for instance--only one Casa Blanca is still hanging on with one last bloom that probably won't last beyond today.

Kate

I'd agree that inconsistent watering is the base problem. Most garden lillies do best in well-drained soil which is regularly watered.

From the description though, some of the lilies are also showing signs of developing botrytis (the 'pheasant-eye' spots) which can be quite damaging.

Pick off any affected leaves as well as any yellowed and dead ones and put them in the garbage. Apply a fungicide to help control the fungus (you can also use a spray of dilute milk or bicarbonate solution, but these only work to stop fresh infections and won't kill any current ones). At the end of the season clean up any old leaves and stems and dispose of them in the same way - rain falling onto the spores splashes them up onto the plants to reinfect them; if an infection has been particularly severe some people even remove the topmost level of soil to try to break the cycle of reinfection. For next year try to improve air-flow and reduce humidity.