My first outdoor grow. 4 auto plants

Try not to stress too much about night temperature until it happens dude , most strains have got a certain amount of resistance. If worried garden fleece can be used in case of frost ,covered at night taken of daily should protect to -5 . Always the riper the better if we can . Safe growing dude .

As alluded to by Dilligaf and considering that the blueberry isn't an auto, you might want to cover it or something and reduce the light for a while, it'll help induce flowering from what I've seen.

Hey mate your blue Berry og isn't an auto is it? If it pheno keep an eye on it might not be fem or it will just start to flower when day light starts decreasing