Neobenthamia gracilis - Orchid Board

nancy · #1 12-06-2009, 03:50 PM

Greetings -
This is called a terrestrial, but I have read many warnings against 1) planting too deep and 2) keeping too moist. Does anyone have some good recommendations for a good potting mix for this (for primarily outdoor growing in the deep south)? I have found that it can be planted in the same mix as Phaius, which would be dandy if I grew Phaius...since it will be outside most of the time, and we can get daily rain for months, it will need to be something that drains pretty readily.
It sure is a tall, grassy rascal!
Thanks - Nancy

King_of_orchid_growing:) · #2 12-06-2009, 05:32 PM

IOSPE PHOTOS

I'd say try either pumice or a well draining cactus mix.

nancy · #3 12-06-2009, 07:49 PM

I see IOSPE lists it as a lithophyte also - though mounting it to a rock would be a sight - not sure if it is blooming size, but it is well over 4', and looks like millet or some other grain. The photos of the flowers really look lovely.
I checked, and it is now in a pretty chunky bark/charcoal mix (Oak Hill's Greg Butler was a speaker at our orchid society's annual short course).
Where would I get pumice here? Do you mean giant chunks of lava rock or something like it?
Thanks again - Nancy

Mahon · #4 12-06-2009, 11:31 PM

Nancy,

A well-draining medium is nice, however the plant still needs to retain some moisture. The underground roots of Neob. gracilis become quite tuberous with age, while the thread-like roots will form at internodes and just below the soil surface.

I've found the best way to have Neob. gracilis and certain Phauis outdoors is to use a typical indoor/outdoor potting mix with a very course substrate (rocks or limestone shards work quite well), but pot in a larger container. In FL, Neob. can achieve great proportions in just a couple years outside, and the same may be said for LA. Cut back watering during winter, perhaps twice a month (if no rain). Try to introduce the plant into full sun gradually if it is grown in shade.

King_of_orchid_growing:) · #5 12-07-2009, 12:52 AM

No, not large chunks of lava rocks. Small pebbles of pumice. Nurseries should carry them.

I'll tell you a brand I'm using and you can try looking it up.

I use Uni-Gro Premium Organic Pumice.

Pumice retains water very well. Acts very much like perlite, but pumice is heavier and will not float all over the place when you water.

If it's not retaining enough moisture, add a tiny bit of loose woodland topsoil.

Bloomin_Aussie · #6 12-09-2009, 09:12 AM

I've had one growing for about 10 years in a coarse mix of aged pine bark and aquarium pebbles. It doesn't look like a plant that would be too easy to kill but then maybe it is just my climate that keeps it happy.

Rosiefuture · #7 04-20-2010, 12:33 AM

Hi Dan, I don't know where abouts in Oz you are but I'm just south of Perth. I have one of these and it's got quite big, it's probably getting on for 50cms. I lost the label but someone was able to tell me the name of it on the indentification forum. It seems to like the WA climate and flowers on and off most of the year and throws keiki's like crazy.

Marion