Try tugging on the dry leaves. If part of the plant comes up with the leaf with very few roots on it, you have a root problem. Voles, maybe, eating the roots, or crown rot.

Sandy

No voles here and it isn't rot, the leaf just comes off, nothing from the ground.

are they under maple trees???

ken

No maple trees, closest tree is locust. No other hosta in this bed is effected.

Flowergirl,

Can you post some pictures of the damage? I really can't tell what is going on. It could be that something is preventing water from getting to the roots of your plant or it could be a blight. It's not likely HVX. HVX doesn't kill the host plant.

Steve

You might have (Southern) blight when you can pull off the leaves and the end of the leaf stalk is mushy, and it smells. There you would need to use a Bayer fungicide with tebuconazol or Terraclor, that one is expensive. I got this information from a posting by Bill Meyer. I presently have that on one plant and found that my other fungicides do not work. It is probably cheaper to buy a new plant, and do remove the surface soil with soil in the hole.
Bernd

i think.. locust is as bad.. if not worse.. than maple.. and that is saying a lot

how close are they ..

i speculate.. that your hosta are basically not getting enough water due to tree root competition.. and they are suffering from drought.. and/or the effects of summer dormancy ...

dig out the SS in a 2 foot circle.. and clean out the soil ... and tell us how many pounds of root mass you take out ... then put all the native soil back in the hole ... and replant the SS...

below is a pic of maple roots .. and why.. you can not garden under them ..

if you stressed most plants.. this bad.. they would simply die.. the first time ... i goes to show.. how resilient hosta are.. that they actually come back ...

increase water 300% .. at least 1 to 2 inches.. AT DEPTH.. per week ... of course.. since they have already started yellowing.. those leaves are not coming back.. but lets clear out the roots.. and see if we cant get a big summer flush ..

ken

{{gwi:208954}}

Bernd-I don't smell anything when I pull a leaf off. I drenched it with benomyl, but I do have some terraclor, so I'll try that. There are 6 0ther hostas in this bed and they are all right. and no its not hurting for water, even tho its 102 here today.

I had two other plants with crown rot, but after pouring my fungicides over it they recovered. Probably what you have to do is dig it up and see what is the problems : few hosta roots left or tree roots, etc.? Perhaps you should pot it up then and place it in a shady spot for observation?
Similarly with your S&S.
Bernd