In article ,
"Dwayne" wrote:

Don't know where you are, but grapes are very susceptible to fungus. A
friend of mine who happens to be an expert on grapes told me that I had to
spray mine at least once a year with a fungicide called Captain (Cap-tain).
You might try doing that after the leaves are on, but before blossoms come
out. If that doesn't solve your problem, next year spray a second time on
the last safe date before harvest time.

Dwayne

snip

Thanks, that's a good idea. That could be the problem. I haven't sprayed
as soon as the leaves come out (and they sure are slow this year)
because we've been eating stuffed grape leaves and I'm always concerned
that the sprays won't wash off.

Maybe we'll give up eating the leaves & spray.

We're in Zone 5. My MIL said we'd have to spray, but she thought it was
when the blossoms come out.