Fusarium and verticellium wilt are nasty conditions. Depends on how far gone the plants are. If they are looking bad, you may need to just dispose of the plants (NOT in the compost pile!) before it spreads to more of your garden.
If they are only a little affected you can try either a baking soda in water solution:
1 tablespoon of baking soda
Ã‚Â½ teaspoon of liquid soap
1 gallon of water
Be sure the soap is soap, not detergent, which can harm your plants.
or a solution of milk and water (any where from 1:10 to 50:50)
Has to be one or the other, they would tend to cancel each other out. But you could try one and then a week or so later (or after the next rain) try the other...