Hi, Clematis should do very well in New Jersey. There's an old saying about clematis "they like their heads in the sun and feet in the shade" which pretty much describes their perfect growing conditions. Basically, they need full sun ( at least 6 hours a day), but they like their roots cool so mulch your plants or plant your clematis behind other perennials that will help keep the roots shaded. Clematis are basically early summer bloomers, although some varieties will continue to flower on and off till fall. You can plant two of them on a trellis if you like as long as the trellis is large enough to provide both clematis growing room.