Should I Trim them a bit to allow the new growth on the bottom to form? They have become very tall. not sure what type of hibiscus they are..but when they bloom they have beautiful red flowers
No, trimming them now can lead to their death very fast. You will have to correct the issue before you prune them. If you only prune them without treating then they will grow back with the same problem. You will want to prune these, either in Spring or Late Fall after it cools.
Now, most common reasons for the symptoms you are seeing are heat without humidity, low soil nutrients (they are heavy feeders and need to be fed once per month or more to be happy.), and lack of light.
There are a few other causes too, but to get to those you will need to rule out the above first.
These articles will offer more information: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/tips-for-pruning-hibiscus-plants-when-to-prune-hibiscus.htm
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/how-to-care-for-hibiscus-plants.htm
My mom's 20+ y/o hibiscus bush looks like it is dying. Located in Pinellas County FL. Weather temps have been HOT (95-103F) and have had a lot of rain. Began looking poorly three weeks ago and garden center recommended copper for bugs and yellowing leaves – then leaves began to drop quickly. Arborist visited a week ago and said maybe getting too much water and saw some eggs on a leaf. Mom put a small amount of fertilizer near base on the ground. A new neighbor moved in a month ago and brought in a few plants/trees (maybe they had some disease?). Mom (90 y/o) is distraught over this. What can I recommend? Is it possible bush is dying of old age?
My first thought was advanced age. Hardy hibiscus is a long-lived plant, and 20 years seems to fit that bill.
Here is general care info:
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/outdoor-hibiscus-care.htm
g? zone 7b Plant in question---Confederate Rose Hibiscus Potted for 3 months in mostly sun conditions Plant is 3ft tall, healthy but has not bloomed
It is much more stressful to move from ground to ground. In container, you don't rough up the roots, break them, or otherwise disturb them much. When you transfer from the ground, you are snapping valuable feeder and support roots.
This article will help: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/transplanting-hibiscus.htm
Name of plant althea hibiscus
Rose of Sharon or shrub hibiscus is pruned when dormant, late fall or winter. Most flowering shrubs benefit from removing 1/3 of the branches, starting with largest/oldest ones, to the ground. Old wood flowers less than young healthy growth and shrubs can get crowded and prone to disease if only the tops and sides are cut back. The following article discusses how to best prune your shrub. https://www.gardeningknowhow.com/ornamental/shrubs/rose-of-sharon/pruning-rose-of-sharon.htm
These worms have stripped the blooms and foliage from my hibiscus leaving only the stock.
Try using Bt if you see any more. Here is more information:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/using-bacillus-thuringiensis.htm
they be watered? And is it ok that they are dropping their leaves even the same ones? Can you tell me what zone I'm in? I think it's 8.
Yes, you are in planting zone 8a. Hibiscus like moist soil, but not wet. So water often enough to keep the soil moist. Dropping leaves could be a sign of overwatering or underwatering.
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-8/zone-8-hibiscus-plants.htm
Have had this plant for about 2 years, and it happened last year too. After blooming quite well and profusely at the beginning of spring, the following buds turn black and fall off, and the plant doesn't have any more flowers through the summer or fall, just a lot of black buds,. It's sad and frustrating - what can I do?
Do not allow them to dry out between waterings. They need regular, deep irrigation. Also, be sure to fertilize regularly during the growing season.
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/how-to-care-for-hibiscus-plants.htm