Laurie,
the spagnum peat moss is useless in the soil, since I am guessing that you want to plant it in the ground, right?
What is your soil like?
If clay, (which is orange) you have to add composted manure in the soil real good, a nice amolunt of space for the plant. Composted manure is organic matter and it will help with drainage which is what the gardenia needs.
You can put a fertilizer on it if you want, you can add it to the soil when you mix the soil with the composted manure.
You dont have to really.
Then you must apply pine mulch all around the gardenia, but not up to the stem of the plant, to conserve moisture for it.
If your soil is sandy, again, add composted manure all around where you are going to plant it, mix in real good with the sandy aoil and mulch real good with the pine mulch.
If the gardenia protests a little after you plant it, don't get upset, they protest occasionally by their leaves turning yellow, but they will get green again.
Don't plant in a full sun area, sun in the morning, but not in the heat of the day.
Good luck, this time your gardenia will be fine.
Just don't kill it with too much love, just water int he morning when the soil is dry by the roots.
Gardenias are very resilient bushes.

who wrote the comment above is slightly wrong... Peat moss has many uses for the ground such as adding air and room for roots to move in clay soil. Peat moss in sandy soil can actually help hold moisture. But Peat moss is a must with almost every acid loving plant there is, and is also the main way to make your soil acidic which is a must for gardenias and blueberries. I add peat moss to my blueberry patch every couple of months just to make sure it stays acidic.. I know this is an old forum but I felt the need to correct the person above me. Look up any site about gardenias and it will tell you that peat moss is very good to mix in soil for gardenias.. in-ground or in pots..