Take a wild guess at which offers more overall light(I know man),but it's the truth. Or split your flats 2 to 1. The 2 maybe on your best hunch. Then monitor and adjust.

Outdoors!!

I go with outdoors also. Actually, true outdoors, not inside a GH. They will get as much of the light they use in photosynthesis in eight hours outside as they will in 15 hours from grow lights, even if the light levels (Lux or Foot candle measurements) are the same. Plus, they will get to experience wind, something that is really quite valuable in the long run. You can always move them inside of a night or if the weather conditions are not favorable.

Mike

I am in your zone and your seeds are usually planted in the fall. These will do very well outside, in the open without shade. If the weather gets warm before they are ready they will bolt to seed, which is why they are started much earlier, normally. Al

Thanks for the input! Yes, I've got fall-planted broccoli and cabbage still growing, as well as some winter sown. In my foggy spot, I should be able to get an early spring crop in as our temps don't really heat up until June. At least...that's the plan. I'll see what Mother Nature has in store. If it's anything like last year, I could have grown broccoli all the way to September!

These are all cool weather plants. There is no reason why a california grower should even consider growing them indoors. Even the warmth of an unheated greenhouse should not be necessary. You would only want to start these plants indoors where you experience subfreezing temperatures for several months.