Good mixes for Dens and Oncidiums?

[Lissbirds]

I'm currently exploring my options for potting media as I'm having some trouble with my current media (S/H).

I saw the sticky above where everyone raved about the phal mixture of coir, charcoal and perlite and made up a mix of it at repotme.com and I'm going to try it out on a few of my phals.

I have a den, which I believe is probably a den/phal hybrid, and I was wondering if anyone can recommend a good formula that has been successful for you--either a custom mix or pre-made store-bought mix that you rave about.

Same question goes for an oncidium I have. I don't know what kind it is unfortunately (I rescued it from Lowe's, if memory serves me correctly), and it's looking a little sad. (I should post a picture for reference.)

Any insight would be greatly appreciated. Thanks!

[domresvanis]

Hi there.A good mix for den is 5 parts of aged pine bark 2 parts of charcoal and 1 part of scoria.For small pots size 1 cm for bigger 1.5 to 2.00 cm.
Good growing...

[Rishad Kalarikkal]

thanks domresvanis....

[lmartiny]

I just buy the Orchid Grow bark mix at the big garden centers. I know many mix their own. Some one else will pipe in I'm sure.

[brookn]

My Dends are generally in bark mixes, I have one that is doing great in s/h. For my Oncidium, I have started to move over to more moisture retaining mixes. One in s/h, some in sphag, one in mostly rock (it's a strange little one), the one in rock has a sibling in sphag, and others in bark that as I said I am mostly moving over to sphag. I would not recommend the sphag for most beginners, as it is something that you really need to be comfortable with, and it is easy to rot roots if not careful. Bark worked well for me, but I have to be on top of watering much more, than with other mixes. Hope that helps.

[Lissbirds]

Thanks everyone!

I was thinking of buying the den mix over at repotme.com and it's mostly coconut husk chips and volcanic rock and charcoal--pretty close to domresvanis' pine bark mixture, so I might just spring for a bag of that. Or make just make up a bark mixture.

I personally don't do well with sphagnum. For me, I find it very hard to tell when it's time to water and I've rotted a few orchids in sphag so I usually stick with bark or S/H.

My oncidium is in S/H right now so I might just stick with it and maybe it'll perk up a little. It's got a new bulb coming up which is a good sign.

Thanks for all the suggestions!

--Melissa

[jerrymeola]

Lets start with the premise that orchids can grow in just about anything. It is just that the watering and care varies with the mix. So understand what the items are doing and chose the type that most approaches your watering habits.

Charcoal - the driest medium after bare root and seldom used alone (Tillansia being an exception). When mixed in with other medium it sweetens the mix, removes odors that may grow, reduces the amount of medium that holds moisture.

Sphagnum - the other extreme it holds a lot of water - It is the only medium in which I can grow Phals in my heat. Many hobbyist find they can not resist over watering in sphag.

Bark - the most common medium and the basis on which we compare drying characteristics. I say yo avoid pine bark. It is the cheapest but breaks down too fast. Find Fir bark it is not that much more expensive.

Coco - stays wetter than bark and drier than sphag

Coir - a bit wetter than coco and still a little drier than sphag

Perlite - often added to a mix for volume and to prevent the mix from packing down too fast. It has a very limited amount of water which it can retain.

Chose between Bark, Coco, Coir and sphagnum based on the amount of watering you plants receive. Add Charcoal and Perlite up to 20% if you wish.

Other things can be added. Osmond fiber which is closest to charcoal. Use the s/h pellets you already have in your mix at about 10-15%. It keeps the mix open and moves water around the pot. It works much the same as perlite when mixed this way.

Chose the size medium - small medium large - based on the thickness of the roots. For example, Small for Oncidium and medium for large Cattleya

It is always cheapest to make your own mixture based on your watering habits.

[Lissbirds]

Thank you so much, Jerry, for posting all that information about the various mix ingredients. That's some wonderful information and I'll definitely experiement with some of those ingredients to find what suits my watering habits.

Great tip for use of mixing s/h pellets in with traditional mix. I certainly have a lot of those to go around. What a great idea!

Thanks so much!
--Melissa