Oh my gosh, my Gardenia is blooming!
Having landscaped for others for 22 years, I have never had luck with Gardenias. They are tricky. I tell everyone, if you move to a house with an established Gardenia and do nothing to it, it will thrive. If you plant a new one, they die. Five houses ago when I lived in Duarte there was a 7ft tall Gardenia right by the front door of the little cabin I rented. I did nothing to it and it bloomed it's head off every summer. I think it was a Gardenia "Mystery" or "August Beauty". Like Azaleas, they don't like their roots to be buried and like acid soil. Plants settle and bury themselves. So you're supposed to plant them with the root ball sticking up out of the soil about an inch or two. It looks a little funny at first. I plant them high like one is supposed to but still they die. So, I don't recommend them to clients any more.
Gardenia jasminoides has many varieties and is native to tropical Africa, Japan and China. The common ones we see here are G. Veitchii which blooms over many warm months and grows 3-4ft., G. Mystery which blooms all at once and grows to 8ft or so, G. radicans which is a dwarf, G. "August Beauty" which is similar to Mystery, and Gardenia thunbergii(a separate species than G. jas.) which has large single-petalled flowers, grows to 10ft and has a different sort of scent than the other Gardenias.
A few months after we bought this house my friend Jay brought me a Gardenia plant he said, "Because it was cheap at Home Depot and I couldn't resist". He always brings me plants. :-) I'm thinking that I'm going to kill it even though I am a good gardener. So, it sat in a pot for about 1, 1/2 years until I planted one of my last beds underneath our big Cedar tree last Fall. I unpotted the Gardenia and found there were 3 plants inside. I separated them(ripped the roots apart) and planted all three; two under the Cedar and one by our Tangerine tree. One died and the one under the Cedar bloomed today. It smells so good!