The only time I have used coco husk mulch was outdoors and it was a total disaster. The mulch quickly turned into a mass of white fungal mycelium and you could smell that mushroom scent very strongly anywhere the flower bed. I would not recommend using that in your Hoya potting mix. Fir bark is best but the bark you have may work as long as it does not give of a strong smell of pine resin. The third component is not sphagnum but sphagnum peat and they are very different from each other. You could use the peat mixed with bark and then add some perlite or something similar to help keep the potting mix open and airy.

Mike

Ok, I'll definitively skip the cocoa husk mulch then. Thank you for the warning! That was exactly the kind of thing I was worried about. Another reason for posting this questions was because the pine bark smells quite strongly of resin, and I didn't know if it was usable. I'm glad I posted here to ask before using it in the potting mix for my precious hoyas! I'll just use it in the garden as first intended. :) I thought about trying it with my hoyas because the bark is so finely shredded, unlike the orchid bark mix I've been using so far which is a bit more chunky than I like.

And I ment to write sphagnum peat - not moss. Sorry. lol :) English is not my native language, so sometimes things get mixed up. :) Hope my writing isn't too bad.

Thank you so much for your answer! I'm going to go with my regular mix of peat, perlite and orchid bark.

Klea,

I guess it depends on your watering habits. I've been using coir (coconut fiber) for about 8 years and I wouldn't use anything else. I use it for all my plants, which are about 50% Hoyas and 50% succulents. I mix it 2/3 coir and 1/3 perlite. What I like about it is that it's good for many, many years' use - doesn't break down like all-purpose potting mix (which tends to break down in 6-18 months, depending on several factors.) I've seen the fungus Mike talks about when plants are left out during long bouts of rain, but I think it might also depend on the quality of the coir you're using. Since I've been using the brand in the link below, I haven't seen any of that fungus.

Besides not having to repot my plants every 6-18 months, I like coir because it dries out fairly fast and lets me water more often. Some might find this a DOWN side, but I like to inspect my plants often and watering time, for me, is inspection time. Helps me stay ahead of the bugs and other issues that can come up.

So I guess if I were at the beginning of my hobby wanting to figure out what I like best (because we all have our preferences...), I'd probably take two of the same species and grow them in the two mediums that appealed to me most and see what does best with my personal watering habits and conditions.

Denise in Omaha

Here is a link that might be useful: Coco Fiber Bricks

After I posted, I went back and re-read Klea's post and now I'm wondering if we're talking about the same thing. "Cocoa bean" makes me think of chocolate beans - am I reading that right? If so, I had no idea they were making a medium out of cocoa beans. If I misinterpretted, I guess my post isn't as relevant!

Denise in Omaha

Yes Denise it is the outer shell of the coco seed. The mulch smells like chocolate but turns into a total mess under certain circumstances. I found that the coco shells and the fungi that invaded them actually prevented water from getting to the soil and it had to be removed after a fairly short time. The mulch itself was quite appealing and might work in some instances but I bet it would be terrible in a pot.
Klea why don't you mix some potting mix up and just try it in a pot with no plant. Water it once a week and see what happens. You might be surprised or it might turn into a mini mushroom farm. lol

Mike

COCOA SHELL MULCH FAQ

Q: What is Cocoa Shell Mulch?

A: Cocoa shell mulch, also called cocoa mulch, cocoa bean mulch, cocoa bean shell mulch, or cocoa bean hull mulch is simply the shell of the cocoa bean. These shells come off the bean during the roasting process and are separated from the beans by strong air action, thus insuring a dry weed-free product as well as, a sterile product.

The roasting process (600 degrees) sterilizes the organic mulch!

Q: Do Cocoa Shells add nutrients to the soil?

A: Yes! Because of its slow decomposition process, it adds nutrients to the soil rather than draws from the soil. Cocoa shell mulch contains 2.5% Nitrogen, 1% Phosphate, and 3% Potash. It has a pH factor of 5.8. No supplemental nitrogen is needed when cocoa shell mulch is applied.

Common soil conditioner.
Great mulch for roses!
Great in gardens!

Q: Are insects attracted to the mulch?

A: As is true with any organic product, there are instances where insects live in the mulch. This is not a harmful thing and the mulch itself is not attracting insects! Insects that are already in the area will live in mulch as well as, the soil. This occurs in cocoa shells when the cocoa shells are too wet! Don�t over water the cocoa shells. The top cocoa shells should be drying out in between waterings. Feel the soil under the mulch to see if it is moist before watering. Cocoa Shells hold moisture into the soil which benefits the plant material. A mixture of Ivory dish wash soap and water will take care of most insect issues in the cocoa shells. 1.25 T. dish soap to 1 qt. water in a spray bottle. Spray on infested area.

Easily treated

Q: Does this mulch tend to mold?

A: In some cases when the weather is very hot and humid, a harmless mold may appear. This also occurs with too much watering. The cocoa shell contains protein which aids in decomposition to produce humus which stimulates beneficial soil bacteria. This is a sign of the protein at work. Letting the mulch dry out or applying a mix of household white vinegar and water will take care of the mold. 75% vinegar and 25% water. Put in a spray bottle and spray on the mold only. (The reason the mold grows on cocoa shells is because of the bacteria in the rain and water, not the cocoa shells. The cocoa shells are completely sterile because of the roasting process at 600 degrees.)

Harmless to your landscape and has a simple treatment.

�COCOA SHELL MULCH SHOULD NOT BE USED UNDER PLAYGROUND EQUIPMENT
�COCOA SHELL MULCH SHOULD NOT BE USED IN A SHADY AREA.
� IT NEEDS TO BE ABLE TO DRY OUT IN THE SUN TO PREVENT MOLD.
� THERE IS NO NEED TO PUT DOWN MAT UNDER THE COCOA SHELL MULCH.

Being the curious soul I am; I couldn't help setting up an experiment using the cocoa husk mulch and the resin smelling pine mulch in a mix with sphagnum peat and perlite. I cut off a piece of my australis and pottet it in the mix. If the cutting dies I know for sure that the mix is not usable. And I guess I'll find out if the mix will grow fungi and just be a big smelly mess. ugh... :)

I'll use my regular mix for repotting my other rooted cuttings. I don't want to play dice with these cuttings!! The australis cutting is not as precious (poor thing being used as a guinea pig!), as I can always take a new cutting from the rather large motherplant. I'm glad I didn't just go ahead and use it for my baby plants, but instead took the time to ask about it on this forum.

Thank you Mike, Denise and John for replying and sharing your thoughts and experience!

Thanks guys for the clarification. I had no idea. I wouldn't use it only because smelling chocolate every time I water would only make me want to go bake a cake (my favorite way to eat chocolate!)

Denise in Omaha

omg now i want cake..... THANKS DENISE! haha

I totally forgot to give an update on the experiment I did with the cocoa mulch. Here is what happened:

As Mike predicted; there was a problem with fungus growing on the surface. Not a whole lot, but enough to make quite a cozy home for fungus gnats! Not a very welcome guest in my house, so the whole pot got banished and put outside. The australis cutting didn't seem to mind the fungus, and has grown quite nicely. : ) I also put some of the pine bark (which had a strong smell of resin) as a "top dressing" in a couple pots of linearis. There were no problems using it that way, but I haven't yet tried it in a mix used for cuttings.

So the moral of the story is: Stay away from cocoa shell mulch for indoor use!! LOL And pine bark with strong smell of resin? Well, the jury is still out on that one. : )

Thanks for the update. I have yet to try a strong resinous wood in my potting mix but I bet if it were composted or aged a few years that it would work well. I have tried to grow several orchids mounted on old weathered Cedar rails over the years. None of the orchids ever actually attached their roots even even after being attached for several years. I have been wary of these types of wood since.

Mike

I would like to know where you found the bark, Klea...

P� Plantasjen. : )

Oops, evidently this forum can't handle norwegian letters... : )

Thanks, Klea.
I`ve only been able to find the coarse orchid bark at Plantasjen so far.

It's the pine bark used for top dressing in flower beds. Not sure it's suited for use in a potting mix for hoyas. Only time will tell I guess. I'll have to set up another experiment to see if cuttings will like growing in it. : ) I mix the coarse orchid bark with perlite, and also bark and coco chips bought from webzoo.no - it's sold as a substrate for use in terrariums. A bit expensive, but I can't find it anywhere else. : / If you know where I can find coco chips at a cheaper price, let me know!!