I'm in So Cal.

I have Non-GMO, Non-hybrid seeds, which did well before, except last yr. Last yr was horrible, I got 5 squash, 4 zuchinni, couple of lettuce, and everything else only grew to about 20%-30% it's size then started rotting.

I use no chemicals of any kind, and it's 90% soil (dirt) and 10% organic fertilizer.

The strange thing about all this was that the leaves were getting burnt... in 65-70F degree weather.