I believe I've heard you should wait a full year to make sure you got all the roots. It's soooo hard. I have a few holes from some infected Royal Standard and they're just itching for new plants...
Stephanie

You need to wait for all the roots that were or might be left in the soil die. I would think you could replant your
spaces where you took out the diseased hostas next spring. I think I'm right in making that statement but someone else with more knowledge may be able to answer your question correctly.

Connie

You might consider planting something other than hosta in those spots as a temporary planting until next year.

i agree.. move some other perennial from a 'good' spot .... into the 'bad' spot.. and use the new hole for a hosta ...

and either.. sanitize EVERYTHING in the procedure or use two shovels.. and never use the 'other' shovel on your hosta .... and after you set the other plant in .. and touch that soil ... go wash your hands before resuming play in the hosta .... not having surgical sterilization methods available.. i would tend toward liquid antibacterial dish soap and the scrubber sponge .... to remove all plant sap ...

do not cross contaminate your garden ...

ken