Ath,
Nothing is wrong with it.
It dosn't like change, that's all.
It'll be fine.
Yellow leaves are normal in fall.
It's brown you don't want to see.
The plant is upset, it'll get glad again.

I've kept the soil as moist as ever

==>>> most likely its in shock .. as noted above ...

its going into its very slow season ... i am not sure it needs to be kept as moist as ever ... as far as i am concerned... rotting off the roots is your biggest challenge at this time ...

what is your potting media... did you repot.. or is it in the pot you bought it in ...

did you get it in before any cold at all???

i am not sure it needs the added humidity until the cold winter and forced air furnace really start eating up ambient humidity ..

i am not familiar with the bulbs you are using... but wonder how far they are from the plant????

you might want to try the houseplant forum.. as well as the bonsai forums.. to find someone with specific experience ...

good luck

ken

It's in miracle gro potting soil. This is its first year... it's actually about 7-8 months old right now. It's a hardy gardenia, so theoretically I could leave it outside, but the first freeze we got here (25F) resulted in frost bit leaves, and I decided I didn't want to risk it, hardy or not. Those frost-bitten leaves, strangely, have stayed on. I brought it in a few days after that, and about 3 days ago is when half the leaves dropped. They never turned yellow or black... they were still glossy and green, and just dropped.

The bulbs are probably 3ft, maybe from the plant? They're in a typical ceiling fan light fixture (the fan is never on because it hums, so it can't be the breeze) centered over the table, and the pot is on the table. It's a very large pot, which brings the plant itself about 3ft from the fixture. I did some reading about grow lights and came to the conclusion that what's special about those is they have full spectrum light. I figured my daylight bulbs might be the same, but maybe I'm wrong and I need to go buy something special for it?

I'll try the houseplant forum too.

Athar,
Your plant isn't a houseplant at all.
They grow into big bushes outside where I live, and they are very
hardy bushes that take alot of beating.
They hate it inside a house. They love it outside.
Think like a Rhododendrum where you live.
They will complain, pout, if you take them inside.
They will even take the cold rather than be in a warm dry home in the winter. LOL
So let it pout, if you must have it in the house, try to give it natural sunlight, go BUY a moisture meter for a couple of bucks and test the soil by the roots to make sure its dry before you water it again.
Take it in the shower once a week at least, the bush wants humidity, and your house will dry it out.
Good luck keeping it in the house this winter.
Next spring plant it outside and mulch it good.
Although, zone 6a isnt gardenia weather, mabey just dig a hole and put the pot in the ground.
Gardenias are happiest outside.
Good luck.
Don't kill it with love.

butter says its bulletproof in her z8 ...

i am not sure that is true for your z6 ... wherever that may be ...

indoors.. the lights should be about 2 to 3 inches from the plant... to have any real impact ... all i ever used.. were plain old florescent lights.. there is no benefit to paying a premium for foo foo lights.. its all about how close they are ... and it is NOT MEASURED IN FEET FROM THE PLANT ... dont waste money on such.. spend it on getting the lights closer ...

also ... you have a great chance to rot off the roots ... if you water it like you did all summer.. outdoors ...

again ... the bonsai forum .. might get you some good info.. on growing trees.. inside ... even if you never bonsai it ....

you also need to address.. whether a G has a requisite dormancy period.. of which.. i dont know ...

ken