If you live in an area that doesn't get frost and stays milder during the cold months you can let your Thanksgiving cactus grow outdoors. This is usually in Zones 10 and higher. If you are in Zones 9 and lower then you can let your Thanksgiving cactus be outside during the summer months but bring it in during the colder season. Make sure if letting your cactus grow outdoors that you keep it out of direct sunlight.