i bought two of those exact same gardenias at Lowes about 4 years ago myself. I planted them in the August time frame and they today are over 5 ft tall! They load up with blooms and smell heavenly! I have them taken up right now in huge pots waiting to move to the new house with us. I didn't do anything special with mine, Miracle Grow and a dose of good potting soil in the hole with the plant and they were good to go.

Aeiger,
You can plant them now, make sure you put some composted cow manure and mulch around them though.
Your going to love those gardenias.
Hi Nannerbelle, how is the house going?
You must be so excited about moving, I think I would be jumping out of my skin. Let us all know when you move.

Hey Butterfly, it's coming along. I now actually have a roof walls and a well. Things are picking up speed now they have it dried in.