Gardenia (Tree or Large Bush)

Question

We live on an island off the east coast of Puerto Rico with its winter season (now) and its wet season (hurricane time). We have older gardenia bushes which have been shaped into trees, and are now about 10′ tall. Lately leaves are dropping and yellowing near the base; blooms are there, but not many now. The soil is volcanic and a clay/rocky mix that tends to dry rock hard, but crumbly. No fertilizer has been used since we moved here last March. Any ideas on how to make these plants healthy?

Answer 1

Add some fertilizer or compost. It sounds like it may have a nitrogen deficiency but a well balanced fertilizer (10-10-10 or 20-20-20) will help to make sure that it also has the phosphorous it needs to bloom.

Here is more information:
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/fertilizing-gardenias-in-your-garden.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/understanding-nitrogen-requirements-for-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm