I think we need a 'gardenia support group' on this forum! Don't feel too bad, Gardenia's like to make you feel bad, it's one of their jobs. They are into S/M I think.... If you swear at it, treat it like 'dirt' (pun intended, sorry), and act totally aloof and ignore it, it may do better. I am guessing you may be over watering it, but don't quote me cuz I don't live in a hot climate and my gardenia is at deaths door right now. I told it to go and die, see if I care, ignored it and it's starting to leaf out again...slooooowly. It's indoors too.

Don't give up! Maybe hopeful or snasxs or someone who knows more about them will post and help ya out, but I'm pulling for you, don't feel too bad, most of us have been there too.

Hugs,
mersie :D

Mersi, I love you girl. What a sense of humor!! Gardenias into S&M..ROFL Black, leather pots, whips hanging off branches. LOL.

Smirk, I wish I could be of help, my only experience w/Gardenias is container-grown. But I have a few pointers. You live in Az. I imagine it's quite hot this time of year, and soon will be hotter. Even though your Gardenia is in a north exposure, are sun rays scorching? As soon as you said leaf tips turned red, sunburn came to mind. I've never been to Az, but I talk to ppl who live there. They've mention how hot it gets, so I'm only going by what'd I'd heard.
Gardenias like cool temps, especially promoting buds, and moreso, keeping them alive longer.
Do you have neighbors who grow Gardenias?

Gardenias require humidity. Perhaps hosing foliage in the morning will help. (not soil, just foliage.) Of course, watering is important, too, especially since your plant is young, newly planted and needs semi-moist roots for a start. Don't keep soil muddy. What type of soil do you have down there? If it's sandy, that should help as far as well-draining.

One more thing. Gardenias need well-draining, acidic soil. Before you planted, dug a hole, did you add mediums to amend earth. Peat Moss helps acidify soil, but there are other mediums that work, too. If you have a friend, neighbor who grows Gardinias, perhaps they'll have tips. Good luck, Toni

As Merci would say, 'Don't 'beat' the 'denias, and don't allow them to 'beat you.' LOL

i agree it may be roasting if in a sunny exposure. this time of year, the northern side of my house gets full sun due to the change of the sun's path.
try a more shady location or a bit of morning sun only if you can. misting couldn't hurt, as mentioned.
check the rootball of the plant by sticking your finger in there after you have watered. sometimes, the soil within may not be getting completely wet and shedding water if it has been allowed to dry out, especially if it is a peat-based medium.

Toni, you are a riot...leather pots, hee hee!!! ;D

Maybe also to increase the humidity you could put buckets of water around the plant as well?