i recently planted a gardenia in April here in NC (USDA zone 7?)The other day i noticed that the leaves have started turning yellow but my mom says she sees new buds. I thought it was dehydrated as it had not rained in 3 or 4 days so i gave it a good watering but then it rained for like 3 days straight.What's causing the leaves to turn yellow? I am also afraid I planted it too deep, the base of the plant is about one inch lower that the surrounding area, is this a problem?

Also, I just bought a new hydrangea bush and am planning on planting it facing west but under a large cedar tree. Is this a good place for it? I was reading that a composte should be used but i figure potting soil is just as good, am I right?

Sorry for being so long winded!!

The gardenia is possibly hungry and requires fertilising or it's possibly showing early signs of collar rot from being planted too deeply. Have a look just below soil level and see if the bark is rotting on the part of the trunk below ground level. If you scrape away the soil around the tree to bring the soil depth back to the correct level it might be OK. You may need to lift it a bit though and this is no big deal especially if it's been raining. Is the drainage where you planted it OK?
Which leaves are yellowing? The older leaves or the newer leaves? Are the veins of the leaves remaining green or is the entire leaf going yellow?