The "wilt" or whatever it is got so bad that I pulled up several large
plants that were not producing. Also trimmed all the foliage
(infected, dried) from the remaining plants and left ONLY the tomatoes
to (I HOPE!) ripen.

Asked the nursery and they said the weather here (Santa Monica CA) has
been so overcast and humid that fungus or whatever has flourished.

1. I want to protect the remaining plants (volunteers -- not the ones
from Home Despot that I tossed).
Nursery sold me product whose label reads:

"Serenade garden Disease Control: Can be used for organic gardens.
Fungicide that attacks harmful garden diseases." Active ingredient is
QST 713 strain of Bacillus subtilis 0.074%.

This from AGRA Quest, not my favorite among corporate ag. giants.

2. Nursery guy also said that I should not replant edibles in that
area; that I should remove the earth to a depth of (I think he said )
about 6" or more; that it would take "several years" for the area to
recover. (Assuming it is infected).

That sounds pretty drastic to me; esp removing the earth. It's been
suggested by a landscape friend that I PLANT some edibles, even
tomatoes, in that area to see what happens to them. Perhaps wait
until this unseasonable cool and damp gives way to usual summer heat.

What do you think?

TIA