Is this medium ok for my orchids?

[scy]

When I got my first orchid, I had to do an emergency repot and wound up buying a bark mix at my local Lowe's. They only had 1 selection with a bark mix and consists of medium fir bark chips, hardwood charcoal and coarse perlite. It's a large bag, so I'd hate to waste it. The only other medium I have is PrimeAgra, which I used for transferring my dendrobium to S/H.

I wanted to know if I can use the bark mix for my cymbidium and miltoniopsis when it is time to repot them. Currently they are potted in a terrestrial mix. I checked on RepotMe's website and they use the following:

CYMBIDIUM MIX: Small Coconut Husk Chips, Medium Redwood Bark, Coir, Small Stalite, Small Sponge Rock, Rice Hulls

MILTONIOPSIS MIX: Small Coconut Husk Chips, Small Sponge Rock, Small Charcoal, Rice Hulls

I tend to be heavy handed when it comes to watering although I tried to water without drenching it in the winter.

My growing conditions:
- East facing window
- Low humidity
- Varying Temperatures Ranges
- Winter Daytime: 75 - 90 F on sunny days; 60s on cloudy days.
- Winter Nights: 45 - 50s F
- Air movement: The central air vent is above the orchids but is not heavy enough to move any of the leaves.

If I change the medium, will the roots die because they are accustomed to the terrestrial mix? When I repotted my phal from sphag to bark, I noticed that some of the roots shriveled up and turned brown as opposed to the plump roots it had prior. Any suggestions? I'd hate to buy 2 separate mixes since they are in 4 & 5 inch pots. Thank you for your advice!

[RosieC]

If the mix is in good condition (not decaying or smelling) then maybe it could be mixed with other things to bring it into line with what you need.

I'm not good on knowing what needs what, but Cymbidiums in my experience grow a lot of roots in a season, and you are meant to remove about 1/3 of the root mass anyway so I think if roots do die back somewhat then repotting early in the growing season gives plenty of time for new ones to grow and replace them before the winter.

You might need something more water retentive for the Cyms. My mix contains a light foam substance (not dense so will only hold a little water not masses). I'm not keen on something so artificial but the idea is that it is free draining while still holding enough moisture.

For Miltoniopsis I've preferred finer mixes, but I'm not really sure what they prefer. It might be best to repot that when there are new growths appearing, as those will produce new roots. Mine lost a lot of root after it was repotted, but it's new growths put out a lot of new root and so it's doing fine.

[Paul Mc]

If I might make a suggestion here. Look at RePotme.com's orchid mixes for the various plants you have in question. They have excellent mixes that I use and really enjoy. You can also create your own mix which means that you can buy the needed materials from them to add to the mixes you already own.

If you have any questions about what to add or what mix works best for certain plants, they have always been willing to research and answer my questions. Of course, I always buy right after I get their responses as well - except for one time when they said I had purchased the appropriate medium from them a few months back. I think that just shows how dedicated they are to helping you obtain what you truly need, and not just sell.

[scy]

The cymbidium is relatively young. I got it in November with two 2" shoots from a backbulb. Now it's about 12" tall. I am considering changing the medium, because the terrestrial mix is what it originally came in and the medium currently stays very damp. It usually takes about 2 weeks or a little longer to dry out, and that's even when I don't drench it and try to just get it moist. However, I tend to be heavy handed with the watering so maybe it's just me?

I was considering switching it to semi-hydroponics when there was more new growth, but I understand it's not a sure thing, so I'd hate to kill it. Do I run the same risk of roots dying as it adjusts to new medium if I change it from terrestrial mix to the bark mixture I named in the previous post? Will it make a difference if I use medium bark chips as opposed to small chc and med bark chips that repotme uses?

Originally Posted by RosieC

If the mix is in good condition (not decaying or smelling) then maybe it could be mixed with other things to bring it into line with what you need.

I'm not good on knowing what needs what, but Cymbidiums in my experience grow a lot of roots in a season, and you are meant to remove about 1/3 of the root mass anyway so I think if roots do die back somewhat then repotting early in the growing season gives plenty of time for new ones to grow and replace them before the winter.

You might need something more water retentive for the Cyms. My mix contains a light foam substance (not dense so will only hold a little water not masses). I'm not keen on something so artificial but the idea is that it is free draining while still holding enough moisture.

For Miltoniopsis I've preferred finer mixes, but I'm not really sure what they prefer. It might be best to repot that when there are new growths appearing, as those will produce new roots. Mine lost a lot of root after it was repotted, but it's new growths put out a lot of new root and so it's doing fine.

[scy]

Thanks Paul! I did look at RepotMe.com's mixes for the orchids in question and posted them in the original post in caps. I don't really know a lot about the differences in medium options, so I was hoping someone could shed some light. I was tempted a few times to order from them, since they have such a wide variety. However, the shipping costs always deterred me.

Thanks again Rosie & Paul for your suggestions!

Originally Posted by Paul Mc

If I might make a suggestion here. Look at RePotme.com's orchid mixes for the various plants you have in question. They have excellent mixes that I use and really enjoy. You can also create your own mix which means that you can buy the needed materials from them to add to the mixes you already own.

If you have any questions about what to add or what mix works best for certain plants, they have always been willing to research and answer my questions. Of course, I always buy right after I get their responses as well - except for one time when they said I had purchased the appropriate medium from them a few months back. I think that just shows how dedicated they are to helping you obtain what you truly need, and not just sell.

[Ryan.Walsh]

scy: I know what you're talking about concerning the shipping. If you are looking for bark try going to the pet store and looking in the reptile section. I get all of my bark from the pet store (my wife is a HS biology teacher and has snakes ) and the bark/coconut husk is cheaper and just as clean. Reptiles are highly sensitive to chemicals and salts so the barks are very high quality.

My basic mix is two parts large screened bark, 1 part hydroton (Prime Agra etc.) and 1 part hardwood charcoal. During the summer lots of stores sell pure hardwood charcoal around here and making it suitable for orchids is as simple as a hammer and a sifting screen. Just make sure it is pure hardwood charcoal, no additives.

[Paul Mc]

Oh wow, that's a great suggestion Ryan!

[King_of_orchid_growing:)]

Your medium grade bark, charcoal, and perlite mix is fine for the Miltoniopsis. If they're in a terrestrial mix, they shouldn't have been put in a terrestrial mix as they're not terrestrials.

For the Cymbidiums, you can use your medium grade bark, charcoal, and perlite mixed with some potting soil. Less potting soil compared to everything else though.

I know the mix you have is good for the Miltoniopsis.

The Cymbidium, somebody may come up with a different suggestion, (and there are certainly many more potting mixes suitable for a Cymbidium), but as far as I know, I've got some hybrid Cymbidiums growing well in that kind of a mix.

[scy]

Ryan: Thank you so much for your wonderful suggestions! It's not always easy to find supplies locally, so I'm glad that I can easily go to a pet store and find some good quality medium. I will definitely try your mix and see how it goes!

Philip: Thank you for confirming that the mix I have is suitable for miltoniopsis and suggesting what I could do for my cymbidium. Thanks for sharing your wealth of knowledge!

I will definitely repot once it gets warmer and I see new growth!

Susan