Plantastic! (Know Your Zone!)
The USDA plant hardiness zone map isn't just pretty to look at; it can help you decide what to put in the ground and what kinds of houseplants will do well on your stoop, patio, window ledge this summer.
New York City is in on the cusp of zones 6 and 7, which gives you a lot of options, actually. Here are some things that would be perfectly happy in the New York area.
More Zone information can be found on the National Gardening Association's website.