I read your care for hibiscus over the winter. Your suggestions mention that as long as the leaves do not fall off, the hibiscus is acting normally. What does it mean and what do you do if all of the leaves have already fallen off in the past 2 months indoors near a window and with watering only to dry soil?
If all the leaves have fallen off and the branches are still pliable, this indicates that plant has gone into full dormancy. It will come out of it in the spring. Place it in a cool dark place and water once a month until spring. Then bring it back out and resume normal care.
We had a hard freeze in Houston a couple days ago and now they (hibiscus) look to be dying. Should I cut them back now or wait till later?
I would wait. If the stems and branches are still alive, they will regrow their leaves. You should see leaf buds develop where the old leaves were in 1-2 weeks.
We have two new hibiscus that were planted in the late spring or early summer by our grounds crew in our condos courtyard. They are now blooming and becoming very tall. While I am here in residence, I take care of them and want to be sure that I do the right procedure in feeding, and at some time, pruning them so they will be in good condition each fall when I return to FL. I will be here until mid April.
When fertilizing your hibiscus, use a high potassium fertilizer. You can either use a diluted liquid fertilizer one a week, a slow release fertilizer once a month, or you can add a high potassium compost to the soil. Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-fertilizing.htm
Prune back in spring by no more than 1/3 per season. This article will help:
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/tips-for-pruning-hibiscus-plants-when-to-prune-hibiscus.htm
I have a sappy black fungus on a couple of my hibiscus trees. What can I do?
You actually probably have a pest problem of some kind, normally aphids or scale. The side effects of these pests are dripping honeydew and sooty mold. Check the undersides of the leaves for the pests and then treat the tree with a pesticide. We recommend neem oil as it is safe for humans, pets and beneficial bugs.
Here are some articles to 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
My hibiscus plant doesn't look too good right now. It has five flower buds on it. I know the flowers will be beautiful, but there are lots of white dots around the buds & leaves (only on the area where there are buds). I'm sure it's some kind of a bug, but what do I spray on it to get rid of them?
It sounds like it may be thrips. This article will tell you more about them: https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm
We have been very pleased with our trials of using neem oil for killing these kinds of pests. It is safe for humans and pets, as well as beneficial bugs. You can learn more about it here: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
I noticed my Hibiscus plant has some little black bugs on the bulbs, and the plant leaves are yellow. I have two of these plants, the other looks beautiful. I want to take care of this before it ends up harming it beyond repair, and I don't want to spray it down with something which will harm the plant. Maybe something organic will work.
The bugs may be thrips or scale. Regardless, if you are looking for an effective yet safe organic pesticide, we recommend neem oil. You can learn more about it here: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
I have a 3-year-old Hibiscus and it is getting too tall. Can it be pruned?
Do not cut it back until spring if you plan on keeping it outdoors over winter. Then prune back by no more than 1/3 per season. This article will help:
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/tips-for-pruning-hibiscus-plants-when-to-prune-hibiscus.htm