Cattleyas on the rocks

[Zozzl]

I really getting sick of bark due to all the wet weather; the more I come up with plants in rock the more I think I need to make a switch. Here in Florida it seems like the bark breaks down in way less than 2 years and the roots don't do all that great in it. More and more it looks like the root growth in rock-based media is the way to go. I am hoping someone can make a recommendation as far as whether a combination of rocks, (alifor, hydroton, lava) is the way to go or just try something straight. A friend of mine likes to use charcoal in her mix and I am just unsure -- I just know the roots growth I see in rock is just so much better than bark, at least in Florida.

Sometimes I do like to use peanuts for the bottom of pots because it is lightweight but I know some folks think that is not so great. For me the bark is about $15/2 cu and the rock seems to run about $22 to $25 or so locally. I thought adding the peanuts on the bottom of the pots would make it cheaper and lighter although I know they are not great for the environment, but I don't see why they can't be reused and I kind of like them.

The differences between the rocks is confusing too because everyone seems to swear by a different one.

Any comments or suggestions would be welcome.

[poetiscariot]

I get orchids from a big-name Hawaiian grower once a year and most of the plants I've gotten from them have been potted in pure charcoal. That's another hot, wet environment like yours, so it might be a vote to try charcoal. I repot all those into bark/charcoal/perlite mixes on their next growth cycle, because I want more humidity at the roots than that, but I'm growing in my house in upstate NY, very different conditions than yours.

I also might mention one rock substrate you didn't -- diatomite. It holds less water than bark but more than lava; it's lightweight; it definitely doesn't break down fast. People use it a lot for Australian dendrobiums, and I'm thinking about getting some to repot some of my more temperamental cattleyas. It seems like it would be less likely to rot roots than bark but would still let me keep fairly even moisture.

[Gin]

I grow a lot of my Catts. in Hydroton pellets the quality of bark is not what it used to be and is too expensive to ship and hardly last a year before starting to break down .. Happy Growing .. Gin

[Zozzl]

The diatomite seems to absorb fertilizers from what I read and I do want to reuse it. What is the difference between the hydroton and the alifor? Is there any point in throwing some charcoal in there?

[poetiscariot]

Anything porous will absorb fertilizer. Soak it before reusing, if you're really determined there?

[cdayinflorida]

Pat, What kind of rock are looking to purchase? I use lava rock for most of my Catts, especially the bifoliates (you know how they hate to be repotted). I use the red form and was able to purchase it at a rock and gravel place, here in Seffner. It was CHEAP!

[Jason-UK]

For me the bark is about $15/2 cu and the rock seems to run about $22 to $25 or so locally

Try getting a wholesale deal especially if you need to buy other sundries from the same place. Worked for me in the uk when i was setting up the vivarium and changing most of my orchids to Hydro and I have no where near the amount of orchids you do. Use the phone to strike a deal if you feel you couldn't barter face to to face or even email if they are on line.

[Zozzl]

Thanks everyone for the help Cathy, do the rock and gravel places call it lava rock? I know there are some of these places nearby, so that may that may work really well! Is this the gray stuff you are talking about or the red stuff? LOL!

I have been using bark for a long time and before that it was tree fern, and way back when it was osmunda which I why I sound so dumb on this. Hey, am I the only one who remembers potting sticks?

[pavel]

What is the difference between the hydroton and the alifor?

Just different brand names.

Is there any point in throwing some charcoal in there?

Not really if you're going straight rock/hydroton/dolomite.

[paphioboy]

You can use straight limestone for a lot of orchids. They make excellent roots in just rock, provided it is humid enough.