The gardenia seems healthy otherwise (purchased from a garden centre about a month or less ago); however, any new buds that appear, do not open, but continue to dry out,rot,fall off. It is in direct sunlight and the soil is watered but not drenched.
Any advice would be great! Thank you!
Thank-you for contacting Toronto Master Gardeners with your question.
Gardenias (Gardenia jasminoides) are beautiful plants and their scent is lovely. Your plant looks to be one of the star-shaped, single flowered varieties (perhaps G. jasminoides ‘Pinwheel’ or ‘Heaven Scent’). These plants hail from warm, humid climates and they are quite finicky in their requirements. They require a moist but not water-logged, slightly acidic soil. While they do need a good amount of sunlight, too much sun can cause bud drop. Since your plant is otherwise healthy and you are watering it well, this may be the problem. There are many other possible causes of bud drop, however, so I am giving you a link to an article on this topic:
https://www.gardenia.net/guide/gardenia-bud-drop-problem
A previous TMG answer to a similar question regarding gardenia care also has some insights:
https://www.torontomastergardeners.ca/askagardener/need-help-with-gardenia/
I hope you find a solution to bud drop so that your plant will continue to flower through the season.