@Margarette When you say you have planted this year, when are you talking about? It's too early for you to have those vegetables growing right now, even in southern CA.
If everything is affected every year, my guess is that it's the soil - did you spread a ton of manure on it that wasn't composted? Or water - are you watering it enough?
Or, are you watering it during the day when the sun is out? That will burn leaves - if you put water on them during the hot sun, they'll fry.
But, there are just way too many variables for us to do a guessing game that will do you any good.
So, give us all the data you can. What soil is in your garden. Are you fertilizing and with what and when. When do you water - what time of day and how often. When do you plant - what time of year. What is the weather like. How much sun does your garden get. Did you spray with anything, whether labeled organic or not.
I have faith that the people here can help you figure out what's wrong and how to fix it. We just need more data.