Grow tomatoes!

"Rooftop space" sounds so wonderful!

You might check and/or post on one of gardenweb's regional forums, & also look for local herb societies, succulent societies (I'm amazed over & over at the depth of knowledge these very specific "fan clubs" have), & local garden clubs.

Remember your parks & botanic gardens, too.

(I once asked about a plant at the Ft Worth Botanic Gardens, & the receptionist said, "I'll have to call a gardener for you" in the same tone that a nurse might have said, "Doctor will have to answer that."

I loved it!)

Local gardeners are your best resource;

they know the conditions, possibilities, & perils.

Good luck, & have fun!