Warmer temperatures and new technologies help an industry once lost to freezes. Harriet Beecher Stowe lived in an oasis of oranges, her windows overlooking groves of golden fruit and silky blossoms.

There’s nothing like a juicy clementine. Many people would like to grow their own clementine citrus tree. However, clementine fruit trees require warm temperatures above 50 F (10 C), and much of the ...