Ciao Arthur and welcome. Your cool-weather cauliflower and broccoli should be ok. I've never grown them myself, but trying this year for the first time with direct sowing as soon as the threat of frost is over. Here in Toronto, that's usually mid-May. If you can't get light on your nightshades (tomatoes n
peppers), I'd buy those babies at a nursery when you're ready to put them into the garden. Garden-worthy size for tomatoes is roughly 8" - 1' and you want to bury those stems all the way up to the first true leaves. They'll make roots all along that stem and grow big n strong. The
seed leaves (cotyledons) are skinny and smooth-sided so it's easy to tell them from the true leaves. In addition, by the time the
plants are ready to go in the ground, the cotyledons are usually withered and sometimes have fallen off all on their own. If they're still there, don't pinch them off, just bury them. The experts say that giving a tomato
plant an intentional owwie can invite foliar disease, just like an open owwie on our own skin invites infection.
Garden-worthy
peppers are about the same size and since you're in Maine, you don't want them any smaller than that or you won't get a good harvest. My experience in
zone 5 is that the more colourful bells like yellows and
lilacs take longer to colour up than the hot varieties like serrano.
Just my 2c Cdn.
Buona fortuna,
Julianna