Norcal grower here. Been at this for year number 3 now. My question is why do u need to acclimate your plants to the outdoors? I had 3 that I tried to acclimate to the outdoors in their pots and they just fried up on me. Yet I put 4 others outdoors and just transplanted them the same day and they are kicking more ass than the others. I just dont get the reasoning. For an idea of how I am rolling the bed is a plot that I dug down 2 ft and filled with promix and ammendments like any old organic gardening guru would, castings, dust, kelp, alfalfa, horse and chicken manure, yada yada sing song. Whats the big deal about acclimating them? They seemed to take better when I just tossed them in! Running cherry pie, purple kush, purple trainwreck and purple diesel.
How big were the pots you pot the fried ones out in? The only thing I can think of is you had small cups that warmed up on you. The ones in the ground stayed cool. Not sure though. Did all plants have same sun? Or some in more shade? I set them out in full shade for a few days. Then morning sun for a day or so. Then set them out for good.
I'm assuming you had them going indoors for a minute, in which case you need to harden off your plants so the change in light(quality spectrum intensity etc) doesn't shocc the plants. To harden off your plants leave them in a shaded area for a day or two before placing in direct sunlight.A few hours should be sufficient but a day at least is recommended.
For starters your going from indoors a controlled environment to outdoors an uncontrolled environment. Also outdoors even on a cloudy day your plants are quite often are getting far more lumens then indoors. Also if your taking them outside when it 90+ degrees make sure your plants are well watered for the day, grow pots can dry out fast especialy the smaller ones. Plants in the ground can handle hot temps a lot better then plants in a pot. The reason is that in the ground they have a lot more earth as in dirt, compost mix, super soil or whatever to insulate the roots better from the heat. Sudden changes in temps and light intensity can stress some plants to go hermie or go male if it isn't mature and or hasn't shown sex yet. I`ve even seen some plants look like they had some leaves on them get bleached from being put in direct sunlight the first time outside.
You normally "acclimate" or "harden-off" any seedling that was started inside, before putting it outside. The main reason is the introduction of UV-A and UV-B rays. Also for wind and temperate changes. You, being in cali, wont have much of a temperate change, but for me in the north east, starting seeds inside @ 72f and then placing them outside in 50f is a big shock for plants.There is way more indepth reasons than i can explain, but if u require more information, check out hardening off plants.
Oh and I also get 100% germination rate with any company's seeds and never lose one plant throughout its life unless it is eaten by deer. Not bragging but just showing that babying these young ones is not so necessary as it is to provide nutrient rich and bright environments.