Hosta growers need to learn that hostas require moisture all the time. Do not complain if your hostas do not do well because of lack of water. If you are not going to water, do not grow hostas!
Two years ago we had a terrible drought here in northeastern Indiana and I watered every day from 7:00 AM to 7:00 PM. The area in question is a better part of half an acre and some of is in shade.
Many other plants were neglected and they suffered. The next year, I was recovering from radiation treatments, and again, some plants were neglected. I no longer have irises. I have weeds, overgrown grass, and an enormous amount of poison ivy. But my hostas were beautiful because I focused all my energy to hostas.
Unwatered hostas will burn and go dormant. They will grow when watered consistent, but the growth is minimal.
Water your hostas every day, especially if is raining or is going to rain.