I'm a newbie to gardening. I've planted a variety of new things, none of which has been affected by whatever is eating the hostas and the rose bush, both of which were already in the garden when I moved to this house in October of last year. All the lower leaves of the hostas that surround my tree out front have lower leaves that look like this. And this rose bush, which seems otherwise very healthy and is putting out some lovely flowers, has leaves that are pocked with holes too. The only thing I know in my limited experience with flowers is that snails can make holes like that. An ex-roommate also had a lovely home with a huge back garden, and her hostas were routinely nibbled on by deer. But they didn't make holes, they just nibbled those plants all the way to little nubs. What can I do? :'(
Slugs or snails could be the problem with your hostas. The roses may be getting munched on by Japanese beetles.
My thoughts were exactly the same, but do you have J. Beetles emerging there already? ours usually don't emerge until July...just as the raspberries are getting fully ripe. For the slugs use a slug bait from the garden center at any big box store. the most effective I have found is a carbryl based one. If you want to go all natural or organic try diatomecious earth or a copper based slug killer. Other people use beer traps for slugs, too. I don't, I don't have the time to mess with that.
I've been using Sluggo with great results. It is safe for pets and wildlife that eat slugs. Beer traps are containers with beer set at the soil level. They happily drown themselves. You have to maintain them and keep protected from rain.
I am sure you found help by now but I have used sluggo with good results . Years ago I had such large flower beds at the other house I just used my husbands beer. You can use a small container, I think I used a small margarine tub. It is best if it has straight sides so they don't crawl out. Dig the ground so the dirt is right at the top of the side of the container...so the slugs can crawl in. I used beer because I don't like it and at that time it was cheaper than sluggo. I will warn you that the beer will really smell if it sits too long in the heat...maybe it was because I don't like the smell of it... and make sure your dogs don't drink it up. Mine would of done it if they could of gotten at it...they usually don't go in my flower beds so I was lucky.