Hi, I wasn't aware that NJ had zone 7; where approximately does it start? Thanks!
It's in the south part of the state along the coast and along the Delaware river. I know someone who lives in Burlington and he's zone 7.
Cuts through the southwestern part of the state then hugging the Atlantic coast to the east until you get to Sandy Hook Bay. I'm on the border of 7a/6b in Monmouth County.
Here is a link that might be useful: Better Homes and Gardens Hardiness Zone Maps
Florafeline, I'm a transplant from New Jersey's zone 6b to 7a ... and what a difference! We've occasionally had annuals like snapdragons survive milder winters, with green shoots followed by blooms from the prior year's brown growth. We're in southern Monmouth County.
It also depends on your local conditions within a zone. If you're in a depression you might be a zone colder and if you are upslope you might be warmer.
For shorter lived things like perennials and such, and things that don't grow tall and can be mulched heavily, I've always been willing to risk more tender plants. I'm a bit more careful with large shrubs and trees, although there are many people who successfully grow trees that are not supposed to be hardy here. I just worry that I'll grow a wonderful plant that will die in that once in a decade below zero cold spell.
You're right Ward, it is heartbraking to lose a mature tree or shrub. I've a friend in Florida who has defended tender shrubs from occasional frosts with Christmas lights and light blankets ... looks strange, but it works.
You're right about microclimates too. We're surrounded by a small crescent-shaped bay, which keeps temperatures here just a tad warmer in winter and, with the added help of lots of mature trees, noticeably cooler in summer. More than once I've run out to the market less than 2 miles away wearing the sweatshirt & long pants I needed in my yard, only to get strange looks from folks walking around in shorts and sleeveless shirts! Those zone maps are a great starting point, but it's important to know one's own area. It's often worthwhile to test the limits a little. Where did I see that quote, "If you don't have any dead plants, you're not trying hard enough"?