I have a rope plant or Hoya carnosa that I've had for a few years, but recently it has started to die off in sections. What is going on, and is there anything I can do to save it?
I would suspect root rot from possibly overwatering (even once can do it though root rot can happen in some cases without overwatering). This article will help you determine if it is root rot:
I live in south Florida. My star hoya gets powdery mildew. What can I spray on it to prevent the continued spread of this disease?
The following article should be of some help to you: https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm
I found black sooty-looking mold on the leaves of my Hoya plant. I checked my gardening book and found a picture that looked like what I have. The book said it was residue from red spider mites. Is this correct? If so, what insecticide should I use? I have the plant hanging on my patio. Should I move it inside?
Yes, I would definitely check for mites. They will be very small and will be on the underside of the leaves. When you see webbing, it is usually from mites. This article will help with treatment:
It is true that sooty mold is normally a result of a pest infestation, be it mites, aphids or scale. Neem oil can be used to treat both the mites (or other pest)as well as the fungus. These articles will help: https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
How do I plant hoya seeds?
Hoya seeds need to be planted fresh, so you will need to get them straight from a plant. Sow the seeds by covering lightly and keep the soil moist. Place them somewhere where they will stay at about 70F. They should sprout in 5-7 days.
Where can I find root beer plant (Hoja santa) in Houston? The plant is an herb used in Mexican cuisine.
I would recommend making an inquiry at local garden centers and nurseries in the Houston area. If they don't have it in stock, they may be able to special order it for you. You may even want to check out local Farmers Markets. Also - try searching on-line.
For more information about growing the root beer plant, please visit the following link:
I can't find any images on Google that match the flower we saw.
The image link below looks like a close match - a Hoya bicarinata (Asclepiadaceae, wax plant, pua-hoku-hihi).
Can you root Hoja santa from clippings? If so, what is the process? I am a chef.
You will need to propagate from root division.