Why don’t the buds on my gardenia plant open?

Question

Some of the leaf ends are brown.

Answer 1

There are quite a few requirements needed before they will bloom. These articles should help:
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/gardenia-care-to-get-a-gardenia-bush-to-bloom.htm

https://www.gardeningknowhow.com/ornamental/flowers/gardenia/growing-gardenias-indoors.htm