Good herbs, tomato, vegetable plants in Brooklyn or queens?
I get all my plants at the Brooklyn Borough Hall greenmarket (Court and Montague Streets, 8AM-6PM Tues, Thurs, Sat). Veggie plants are $1 each and have always done right by me. I think herbs are $3 each or maybe 3 for $6, I can't remember. There are several subway lines nearby.
In Flushing, I like Garden World
as well as Keil Brothers
You'll need a car but those two places are within blocks of each other. Garden World is a little bigger and cheaper than Keil Brothers, which is a bit more high end.
Closer to Brooklyn (though you'll still need a car) is the Home Depot on Woodhaven Boulevard, which I have found to be a little larger and better the most other Home Depots in the City when it comes to plants. But get there early as it can be a madhouse on weekends. - Home Depot, 75-09 Woodhaven Boulevard Glendale, NY 11385
Hope this helps you out!
Glendale is hungry...