Well, I'm almost sorry to suggest this on such an old & established plant, but I think one needs to check the roots. Yellowing leaves can be from overwatering or some other drainage problem (like maybe the rootball has hardened off leaving the plant unable to take up water?).

A long time mentor of mine in plants used to tell our Indoor Gardening Club that trying to diagnose a plant w/out unpotting to check its roots is like trying to see through a blindfold, not likely to happen.

From what I've seen w/ some Hoya growers in Calif., Hoyas getting too much sun get a bit faded, bleached out looking (but still feel firm to the touch) & the leaves don't drop off.

May I suggest you take some cuttings off the green growth & pot them up separately in new mix just in case?

If you are afraid of loosing the plant I absolutely agree with PG that you should take cuttings from the healthy growth. What does the potting mix look like, is it old and tired looking? Perhaps the plant needs some fresh potting mix so that it can put out some new root growth.

Mike

I have never taken a cutting from a plant and am not sure how to go about doing so. I am really afraid that I am going to lose this plant. Can you give me instructions as to how to take come cuttings just in case?

Also, the soil looks root bound. I have roots coming up to the top of the soil. I am guessing that this is not a good thing. Should I re-pot the plant into a bigger pot? If I do, what am I looking for regarding the root ball being hardened off? I really don't know what I am doing and I am very afraid that I am killing the plant without knowing why.

Thanks for your input. I really am getting very nervous about this.

Trina

Being root bound is not necessarily a bad thing but potting up slightly larger will give the plant a chance to grow some new roots and provide it with nutrients from some new potting mix. How big is the pot the plant is in now? Usually you would only want to go up one size. If you can easily knock off some old soil do that but if it is all roots you might want to just leave it alone or perhaps soak it in some water to remove some of the old soil if it looks bad or if there seems to be mineral deposits from hard water buildup over the years. A good potting mix to use is soil, orchid bark and perlite.
Taking cuttings is very easy and rooting them this time of year should be no problem. Simply find a healthy vine and take a cutting. If the vine is fairly long you can cut into pieces about a foot long and then plant them with a lower leaf node in contact with or just buried in the soil. Don't worry about removing the lower leaves just trim the stem below the leaves so that it is a couple of inches long before you plant it. Keep the cuttings moist and humid, a plastic freezer bag or an old aquarium is a great help to keep the potted cuttings happy but if you have high humidity in your area it may be fine without. Once you see new roots have developed the plant will be ready to come out of the freezer bag but I always wait a little while longer just to be sure there is a good root system to provide moisture to the cutting.

Do you have a digital camera? Photos would help tremendously if you could show us the plant and the pot/roots etc.

Mike

I will take some pictures before I try and re-pot the plant. I really appreciate your help with this. I am very worried. Colorado is very dry. The pictures are coming.

Thanks,

Trina

Pls try not to worry, you can't ever worry enough to make it better so please, we'll try to help if you'll pls. try not to worrry, OK?

Hello:

your hoya need as little as possible water at the momment and "chelated iron".

My 22 years hoya carnosa had the same problem last summer and now is all OK.

Please, can you see the URL/LINK?

Sorry I dont speak English very well.

Thanks.

Here is a link that might be useful: 22 years old

Pepeuve,

Could you pls stop adding your link to every thread you answer. I've seen it 3 times in the last few minutes. Once or even twice is enough thanks.

Pirata:

Tu no lees el resto con mi consejo.

If you don´t speak Spanish, please, translate witch "google translation".

This message was an advice, not for you.

Do you know what is "quelato de hierro"?

If you don't see some post at my blog. please, simply, ignore it.

It's very easy.

chao