I tried growing heirloom tomatoes last year. I ordered a good selection of seeds in January and built a growing lamp to start early so the young plants would be ready for transplant in March here in Arizona.
It was quite enjoyable and I had many plants ready for transplant when March rolled around. The plants grew well but didnt start flowering for a long time. None of my tomatoes did very well during the spring and summer of 2009.
As the weather started to cool back down, a number of my tomato plants came to life and started to flower out and set fruit. But as the weather continued to cool, the fruit stayed nice and green and I wondered if they would ever turn.
While the rest of the nation has been freezing and buried in snow over the last month, the Sonoran desert has enjoyed 65-75 degree weather (today was 76 degrees) and I noticed some color changes occurring in my tomatoes last week.
One of my Black Krim tomatoes that is ripening in January.
This is a Roma Grape that I planted in September.
I planted an Early Girl in September as well.
In July, I took a clipping from one of my Black Krims and literally stuck it in my Square Foot Garden. I didnt try to root it in water or anything. I thought "if it grows, it grows...". Even in 110 degree weather, the plant survived and grew and here are some of the tomatoes I am getting from that plant!