Hi
Would be an interesting experiment. What type of orchid did you have in mind?? I grow most of my epiphytes mounted on wood /stone or crushed lava rock for those in pots. For terrestrials I use coir mixed with various organic
materials depending on the type. gary

Well, I have a bunch of phals, so I could have a control group as well. Right now, they're all in bark. The gritty mix is supposed to increase drainage and air circulation, two things the orchid needs.

I have two oncidiums as well that need to be repotted after they're done blooming. Maybe I'll do one in bark and one in the gritty mix. They are terrestrial, so maybe they would fair better in the small rock mixture......

I'll soon find out.

I vote for the oncidiums. I don't think its the right mix for Phals. Big roots, big medium - fine roots, finer medium.

I've grown oncids in gritty type mixes with success although you must watch they don't dry out too quickly. I find that mix hard to judge. I like lifting a pot and knowing when it is time to water. You get a feel for it over time. Gritty mix doesn't have that feel.

Jane

Yeah....I'm liking your comment Jane. I think I'll do a test with just the oncidiums. I'll leave the phals in bark.

And I thought I was the trouble maker *snicker* :)

I'm with Jane on this, especially for indoor growers. I think those that are most likely to have success with it are those that are growing in warm, high light greenhouses where they are most likely to dry out quickly.

CJ, I just want to clarify that I am not promoting the use of grit type mixes for Oncids. I tried it with a few Oncids and Intergenerics when I was running into problems with root rot. Again these problems surfaced during winter when light was weak and temps cool.

I'm not sure where you are growing and your zone.

Oncids and the various intergenerics like to stay a bit damp. They are different than Phals in that they are thinner leaf and root and store extra reserves in their pbulbs. If watering is off you can get shrivelled bulbs and wrinkled leaves. Most like cooler temps and some humidity. Grit mixes hold some water but its difficult to tell whether it is dry or not. The mix doesn't hold fertilizer well and I found I started adding some fine bark and sphag to the mix. It opens it up letting in more air and keeping some humidity around the plant.

If you are careful with your watering they should do okay. I don't think its optimal without an addition of some small bark or sphag. But without knowing your growing conditions its hard to advise.

I'll end this discussion by saying that I no longer use this type of mix. I didn't find any benefit and didn't like the 'feel' of it. I'm more comfortable with bark and my plants do well in it. I especially like small bark (fine) with a bit of perlite and bits of sphag mixed in.

Having moved to Florida, its a whole new ball game now and I feel like a beginner all over again. What worked in NY is not working here.

Good luck and enjoy. Orchids take time to get the feel, but they are so worth it. Just keep trying different things and you'll find out what works for you. That is the bottom line. People can only suggest but can't tell you what will truly work for you.

Jane

Thanks Jane.....great post.

I have fir bark fines that I use as a gritty mix component. Would you suggest those for the Onc's??

CJ, what zone are you in and what State? I haven't had time to read all the different threads. Could you post a photo of the Oncids?

I don't know what size your fines are. I don't use gritty mix for my dirt plants so I would need to see the size of your plants and the size of the fines. I like a fine or small orchid bark mixed with perlite or sphag/tree fern for Oncids. If the plants are large and growing in a humid environment, I would go drier using a larger bark. Depends on the plant and the growing conditions.

Post a pic or the name of the plants you are using.

Jane

Jane,

I live on the Jersey shore. I think my zone is a 7 something. Cold winters and humid, almost jungle like summers.

Here is a pic of the bark in question.

Here are the onc's

Close up after watering.

Another shot.

I haven't messed with them much since I picked them up at a show two weeks ago or so. I don't want to bother them while they are still flowering. I can't even tell what they're in right now because of the moss grown all over the top.

Nice and healthy. Yes that bark looks great. Mix bark 80%, with some sphag (torn in small pieces) and some perlite. I would pot them up one size. Put them out in a shady spot over summer. You should get nice growth.

The one on the left looks to be Sharry Baby. Can't tell the other. But I think that one will probably give you the most problems. Never had luck with those intergenerics.I bet there are others who could give you more info on them.

Good luck and that bark looks perfect! Soak it before using.

Jane

Thanks Jane. In what percentages would you put the sphag and perlite?

Use your judgement. It depends on whether your plants are going out for the summer and how wet they will get. I like perlite to keep the mix open but still allowing the bark to hold some moisture. But if its really humid and rainy, you stand a chance of rot so you be the judge. I usually will bring the Phals, oncids and intergenerics inside if the weather gets too wet.

In winter its a different story. If your house is bone dry, you can add a little blanket of sphag on top of the bark which you can remove in the summer.

You'll find your way. Add about 90% small bark, a pinch of sphag (2%) and the sprinkle of perlite mixed in.

With the Phals I'd add more sphag, maybe 80% bark, 15% sphag and some perlite. I'm not good with measuring, I don't do it. I look at the old medium and the condition of the roots and go from there. Its truly a judgement call on your part. You know your weather and your house conditions.

More sphag, more dampness. Smaller bark, more water retention. So you need to figure it out.

Jane

Thanks so much Jane. I appreciate all your help.