Summer is lingering here this year. Had a cool wet spring and early summer. Fortunately for my tomato's. I usually have had my first frost by now. 6,000 ft at the base of the Rocky Mts. Supposed to tickle 90 here today.
I have a friend that grows at 9,000 in the mountains. She has a heated small greenhouse. Some how she pulls it off every year. I give her clones every march and she harvests in Oct. Temps are well below freezing every night.