We live in the Dallas/Fort Worth area of Texas and have two outdoor/in-ground gardenia bushes. Can we trim them and if so how much and when?
Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/flowers/gardenia/when-to-prune-a-gardenia.htm
What should be done for the leaves on my indoor gardenia plant as they are turning yellow?
Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/flowers/gardenia/helping-a-gardenia-bush-with-yellow-leaves.htm
My gardenia plant has not been moved and both watering and light conditions have remained constant. It has been developing buds for three months. They were just about to show some white. There are about 100 buds-it is a large standard. All of a sudden they are falling off. The base of the buds is black. Does anyone know what the problem is? I suspect a fungus. Is there anything I can do?
It sounds like you have thrips. This article will help with that:
https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm
I would recommend using neem oil to treat them. We have found it to be effective against pests like this. Here is more information on that:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
I would like to know when and how to prune a gardenia.
This article will help you:
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/when-to-prune-a-gardenia.htm
I have moved a gardenia plant from my mother in law's house in the fall. I would like to know about replanting a gardenia plant.
This article will help you:
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/transplanting-gardenia-plants-planting-gardenia-somewhere-new.htm
I have two gardenia bushes planted outside that produce a lot of blooms. Suddenly the leaves have turned black with a crispy black film that looks like it is peeling off on some of the leaves. What is the cause of this, and is there something I can do to correct it?
It sounds like you have sooty mold. It is normally a sign of a pest infestations. I recommend treating the mold and pests with neem oil. Here is some information that can help you:
https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
We live in Hawaii and have planted gardenias. Some of them are planted in full sun and are doing very well. Others receive morning sun and are growing well, but the leaves are covered with a dark sticky substance (looks like a mold). There is no sign of white flies. All the plants are on a drip system. Any idea what the mold might be and/or how to prevent? I am considering hand-cleaning with a 30% Simple Green solution.
It sounds like sooty mold. This article will help you: https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
I like neem oil. It gets rid of both the fungus and the pests that cause the fungus. Here is more info on neem oil:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm