Another leaf.
Kathy

Had a nematode problem in several plants, last year. I treated for three days with Zertol then this Spring I dug up each infected clump and rinsed off all the dirt from the roots and then soaked the clump in a bleach solution. So far it looks like I've had about 99% success with only one plant showing minor nematode damage. Oh, by the way, I potted all the infected plants up this Spring and have kept them isolated so I could keep better track of their progress. It sounds like a lot of work, but not really. Best of luck!

I would rip out the affected leaves and spray an icescticide, see below.
I read in the Hosta Journal that about 10 years ago someone already had figured out how to control nematodes. Chris from Halsons wrote years ago that to spray Merit is a solution. For the last 2-3 years I cleaned several infested hostas of nematodes using Bayer Advanced Complete Insect Killer which contains Imidacloprid (=Merit).

This year I used the double dosis of this Bayer isecticide as was recommended by someone in The Hosta Journal by spraying all hostas every month, but all previously infected hostas every 2 weeks over June and July. I sprayed the soil around the petioles, petioles and top of leaves. Today on August 3 I do not see yet any signs that nematodes are inside leaves, and I am in zone 5, usually they would show. We will see in the next weeks how effective my spraying was.
I also spread more slug bait under hostas this year, and there are less slugs.
Bernd

This post was edited by berndnyz5 on Sun, Aug 3, 14 at 14:21

I would pitch the plant and pour boiling water around the dirt where it had been located. Any other option, other than heat treating the plant itself, just reduces the population to keep the symptoms at bay. Unfortunately the insecticide treatments and other treatments would need to be repeated year after year or symptoms just come back.

Sorry to hear you have been sold plants like that.

Chris

It's gone. Directly into the garbage can and two large tea kettles of boiling water in the hole and surrounding soil.
Kathy