My geraniums still look really good. Wondering when to prune them back for winter?
You won't. You will want to prune them in spring, once winter is over. Here are some articles that will help:
If this is a type that will remain green through the winter, then you can trim about 1/3 of the plant off, but this is not necessary for its survival. In fact, it winters over better when you leave growth to protect it.
Here are some articles that will help:
https://www.gardeningknowhow.com/ornamental/flowers/geranium/pruning-geraniums.htm
https://www.gardeningknowhow.com/ornamental/flowers/geranium/geranium-care.htm
I am guessing you leave them outside during winter since you are in zone 9. This article should help:
https://www.gardeningknowhow.com/ornamental/flowers/geranium/pruning-geraniums.htm
This plant is several years old and it had a huge flower cluster at the top. Is this it’s final year and will it now die?
Unfortunately, your photos did not come through. I am unable to identify the plant in question. In the meantime, This collection of articles will help you to gather more information:
https://www.gardeningknowhow.com/ornamental/flowers/geranium
I can not seem to find any information on the viny growth coming from my geranium plant.
That is a parasitic plant known as Dodder! Here is an article that will explain in more detail:
https://www.gardeningknowhow.com/plant-problems/weeds/dodder-weed-control.htm
Can the Raven Cranesville be planted in a large pot? Will it survive in a high heat area (July-October)
It prefers full sun to part shade so if you live in a high heat area, part shade will be best. And, yes, it can grow well in containers. The pot shouldn't start out too large. Just make sure it is larger than the rootball. When you need to repot, only go up one size.
Hardy geranium usually doesn't tolerate high heat and humidity.
https://www.gardeningknowhow.com/ornamental/flowers/cranesbill-geranium/growing-hardy-geraniums.htm
i have 4 indoor geraniums. They grew massive, with leaves as big a my hand with outstretched fingers, blooms bigger than a softball. I've had them for 3 years. "Stretch" started developing limp yellow leaves about 4 weeks ago. They eventually dry out and fall off. I've been VERY careful about not over or under watering. Stretch's condition has progressed from a couple leaves a day to about 15 a day. Thinking she was root bound in a 9" pot, I transplanted her into a 16 3/4" pot.. Shocking discovery that a plant 3' wide x 2 1/2' tall hadonly a 8" dia. root ball. I used good quality potting soil , and was gentle. She continues to die. Meanwhile my healthiest plant "Big Germanium" has SUDDENLY (overnight) developed a DIFFERENT problem. The stem end of her petioles shrank drastically to thread size. There is no yellowing or sign of blackleg. I've given both plants a deep antifungal soil drench (Captan) in the hope they can be saved.
Unfortunately, your photos did not come through. I am unable to see the damage.
There are a number of pathogens that can show themselves, suddenly, unfortunately. It sounds like you are doing the proper thing, though. If fungicides and repotting fail, then it will be necessary to start fresh. That'll mean a new container, new soil, new plants, and everything!
Here are some common diseases that you can compare with, in the meantime:
https://www.gardeningknowhow.com/ornamental/flowers/geranium/common-geranium-diseases.htm
I have some hardy geraniums that have small pink flowers quite heavily veined. I cant remember the name, sorry. Could be a sanguineum variety (vision pink?) Flowering seemed to be finishing and the weather bashed them around abit so i cut them back near to the ground. Will this encourage new growth for another flush of flowers before winter sets in please. Unable to upload photos
Hardy geraniums often don't rebloom after flowering, but cutting it back should refresh it and could lead to a second flush of blooms.
https://www.gardeningknowhow.com/ornamental/flowers/cranesbill-geranium/growing-hardy-geraniums.htm
Geraniums are in pots. Have done this for 20 years and never had a problem. did purchase some plants that looked like something might have been wrong with the leaves, which were brown had a few leaves turning brown but was assured a plant spray would solve problem...if it became a problem. Spray didn't work. Is this more than just a single infestation? Oh, yes; one plant that I've overwintered for a number of years seems so far to be impervious to disease. I haven't added any new plants to the pot. It's the only one i think i can overwinter this year. Am new to reaching out for help because i've never had any problems like this year's; so is there any other information you require? I have no photos or images to send.
Unfortunately, without images of the issues in question it will be hard to say what is going on. It does sound like an infection. This could be bacterial or fungal. Both will be caused by overly wet soils.
fungicides may help, as well as making sure that the plants dry out, completely, down to about 1/3 of the way into the container between waterings. Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/ornamental/flowers/geranium