Seattle urban gardening tips

As we’re all staring down the possibility that we’re going to be facing an economy where everything costs more, I’ve been thinking about gardening. I don’t have a yard. I live in a townhouse. I do, however, have a relatively sizable rooftop deck. Is there anyone else out there growing food on their roofs/balconies/very small yards? Want to share tips? How do you keep your food growing through the dark cold months? How do you keep it lightweight for those of us with rooftop or balcony weight limits? I feel like I need to get some foods growing up there.

I know the P-Patches exist, but im wondering about growing food in small apartment or townhouse spaces.