How do I look after Gardenias

The cold winter could have killed it. Even though a plant is your good for your Zone it doesn't always make it through a bad winter. I know plants do much better if they are planted in the earth. Containers don't always protect them from the cold. The one thing that worries me the most is that the stem is getting the woody. The weather just started to break in the northeast where I live and with warm days ahead it may take a turn for your gardenia plant. It still has a chance it started to sprout leaves.

Hi Janet, I recommend diluting a tablespoon of Epson Salt in a gallon of water and then sprinkle it on the dirt at the base of the plant. This will put enzymes in the soil and should improve the general health of your plant. You can use this method on any flowers or veggies. You can repeat once a month. I hope this helps you.

https://www.gardeningknowhow.com/ornamental/flowers/gardenia/no-flowers-on-gardenia.htm