I have noticed small black marks on the new buds of my hibiscus plants. Are these ants? Do I spray them, or do they help open the buds?
It sounds like it may be scale. We recommend spraying neem oil to treat them. Here is information on scale and neem oil:
https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
There are many reasons this can happen. This article will help you pinpoint which is affecting yours: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/answers-to-what-causes-hibiscus-leaves-turning-yellow.htm
If you plant a hibiscus tree, will it grow back the next year?
It depends on the variety and where you live. Hardy types can usually survive winters outdoors, whereas the tropical kind does not.
My hibiscus gets plenty of buds, but they fall off before they open up. Could you help me?
The plant may have thrips or it could be a watering issue. Here are some articles to help you:
https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-flowers-hibiscus-blossoms-falling-off-plant.htm
My Hibiscus is starting to get droopy leaves and they are all falling off. What should I do?
If you recently brought this plant indoors, this is a normal issue. It is just going through a bit of acclimation shock. Make sure it is getting enough light and water, but expect that it will shed yellow leaves all winter. Most of the time, hibiscus indoors are able to survive, but don't look that great. Not to worry though, they bounce back beautifully in the spring when you place them back outside.
I had a great hisbiscus plant. We had a cold winter this year in Southern GA. It is now just brown. I am not sure if it dead and have to start all over.
As long as the stems are still alive (pliable), it will come back. This article will help you with caring for it with the damage: https://www.gardeningknowhow.com/plant-problems/environmental/tips-for-saving-cold-damaged-plants.htm
This article may also help you in determining whether the plant is still alive: https://www.gardeningknowhow.com/plant-problems/environmental/how-to-tell-if-a-plant-is-dead-and-how-to-recover-an-almost-dead-plant.htm
I've just pruned my 6 hisbiscus - we live in Florida - and they are also in need of their spring feeding. Can I fertilize hibiscus now or should I wait a few days?
It should be ok to go ahead and fertilize now, though waiting a little while wouldn't hurt either. Here is an article that may also help: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-fertilizing.htm