Holes in Hosta Leaves
Holes in hosta leaves a common sight no matter where you garden.
Slugs are the most common culprit but there are other possibilities.
Start by reviewing the weather. Frost damage, like you see here, hail, and even falling maple seeds, many call helicopters, can damage these plants. Monitor the weather and the progression of the damage. No more holes its most likely one of these.
Sink a can of stale beer in the ground near your hostas or check under rocks and birdbaths in the morning. If slugs are the culprit you'll find them there. Continue trapping with the beer or try the eco-friendly iron phosphate products.
Earwigs are the other possibility. They prefer cool dark damp conditions like slugs. Set a crumpled paper out under a pot to trap. If present you can live with the damage or try one of the more eco-friendly insecticides.
A bit more information: Holes can also result from some diseases. Anthracnose fungal disease for example, causes large irregular spots with dark edges. The dead leaf tissue in the center of these spots often falls out. Avoid overhead irrigation, especially late in the day and remove infected foliage to reduce the spread of the disease.