It will probably survive, depending on the cultivar, but chances are you'll get a lot of blasted leaves and young stems, which will set back the next flush of flowering. I'd bring it in anytime night temps drop below the 50s, unless it's one of the "cold-hardy" cultivars like Klehm's Hardy, which can probably deal with a few nights in the 40s.

Good luck, and keep warm!

Jim

No, the pot is not really large. The plant is not a cold-hardy type either. The pot is probably 20 inches in diameter. I will try to let it stay out. The forecast for tonight is 49 degree F. So, I will cross my fingers and see. As it gets cooler, I notice a couple more yellow leaves. I am not sure if this is normal.

Shic, 49 is fine..yellow leaves can either be caused by the season change or, and you must be cautious about this..if you water, do so early..you don't want to water late, then temps drop in the 40's..this can also cause leaves to yellow. I'll keep my Gardenias out till it get turns about 40..by that time new buds should form..Toni

I've always left my potted gardenias out until the temps were consistantly down to about 40F. They've never suffered any damage and bloom beautifully starting in the spring. They experience some shock when they are moved into the greenhouse for the winter, a bit of yellowing and leaf drop for a short time. They do ok but definitely like being outside much better.
Karyn

Oops, we have a few nights in the 30Âs, AND it rains a lot. I think the plant is in critical condition now. Although, for people who do not know about Gardenia, they are still gloriously lush with little yellowing. However, I have plants since elementary school. I detect that the pot keep heavy for 5 days now. It suggests the root is not doing well. Water is not pumped out by the leaves. I have started taking cuttings, just in case. I love this cultivar I hope you remember my pictures earlier this year.