If you have water and the sun shines..... Last winter I had no frost at all up my mountain, so the tomatoes that seeded themselves at the front of the house last autumn are still producing fruit. I picked the first from them on January 1st.
I find the biggest problem is the heat and low humidity, with a drying wind,so if your plants are from hot dry climates, there should be no problem.
My cacti are over 20 feet tall and in full flower