Suggesting how to overcome that is a bit tough without knowing what is causing the problem.

Tough to even guess without pictures of the site and plants. Any chance of that?

BTW, which county do you live in?

la county. Having problems figuring out how to post photos so I will try more later but here is a pic of the stem all hollowed out.

Thanks for your help.

Below is a pic of the garden before problems.

Thanks

Powdery mildew has been horrible in soCal this year.

If that's what you have, try Serenade (bacillus subtilis) or neem oil weekly.

Water only in the mornings, no more than once per week.

Thanks. I probably need to set up a different watering system back there because currently there is some overspray from the lawn. Watering only in the mornings has helped the garden overall definitely.

I did try the neem oil which worked great on the squash but didn't have the same effect on the tomatoes. I also tried a copper spray earlier on the tomatoes when I thought it was something else.

Zone 6A here and am dealing with pith necrosis myself. It's weather and over feeding related. Cool nights with high humidity and high nitrogen levels in the soil. How often have you been feeding your plants? I never knew this disease existed before this. I didn't know you could over feed in ground plants. Suffice it to say I know now. The bacteria that causes this is naturally in the soil. Plenty of sunny days can overturn this issue. My plants have been dealing with it now for over a month. I'm still getting fruit. Obviously I won't get as much fruit but I am getting some. BTW I stopped their feeding. FYI I do remove the diseased branches and I have tried to water them every day to try and remove as much of the nitrogen as possible. This is a learning experience which I hopefully won't have to deal with next year. Hope you have positive results!

Thanks Joe, that's some positive news. Sounds like there is some hope for next year if I can fix the soil. Was thinking about doing a soil test--I think you are probably right, the soil I put in the raised bed probably had a lot of organic material to start with and then I fed pellet fertilizer twice plus I started vermicomposting this year so been sprinkling that too. When the plants started looking weak my reaction was to feed more.

LOL I did the same thing feeding wise. My raised bed had new organic soil and then I began the feedings. You mentioned pellet fertilizer. I fed them with seabird guano (12-11-2) and I fed them and I fed them... LOL....Next year it will be new organic soil and I will foliar spray them with a seaweed/molasses blend and that's it. But as we all know with gardening I'm sure we will have new challenges to deal with. This year I am getting toms from my affected plants and so all of my efforts of germinating them from seed which I started back in March has not been in vain. In fact it has been FUN and I've learned soooo much. "FUN, FOOD and LEARNING" Wow I'm a happy gardener!