lava rock and my orchids

[kindrag23]

How would you have ever guessed?

[james mickelso]

Oncids and most of their relative's bulbs become shriveled when they have produced new growth. It is their natural habit. The new growth emerges, grows leaves and finally a pbulb. The pbulb fattens on water and starches/sugars, and then starts forming one or two flower spikes depending on species. Once it has flowered or starts producing new growth it starts giving up it's supply of nutrients and moisture to the new growth. That is the cycle. My Brassia stays nice and plump until it has produced it's normal two flower spikes and starts to produce two new growths. Once it does that it too starts to shrivel. I like the potting in lava rock Kindra. This way you can water it a lot and that means you can feed it a lot. Keep it warm. I have seen oncids time and time again planted in media that is too small and due to their fine numerous root mass, they succumb to rot. Loose, well draining media like lava rock helps keep the rot at bay. I like the looks of the lava rock you have. It is full of little holes that will hold water while still allowing lots of air flow. If you need to you can moderate the moisture holding ability of this potting by laying a thin layer of sphag on top. When it is ready it will produce new growth. That is what is important in this group of pbulbs. Oncids don't re-plump no matter how much time they are left drowning. They have done their duty and now are doing what comes naturally.

[ALToronto]

The only thing I would reconsider is the clay pot. I have about half of my plants in lava rock or lava/LECA combination, and I just find that plastic pots work better for that.

[kindrag23]

Originally Posted by ALToronto

The only thing I would reconsider is the clay pot. I have about half of my plants in lava rock or lava/LECA combination, and I just find that plastic pots work better for that.

I will try this with another set I have in plastic already.

[kindrag23]

Today makes day three with my dove, gramms,and some oncidium/ondontoglossums in lava rock...Seems to be working great they are all staying wet enough with no issues found thus far.

[Cactuseed]

I second tree fern fiber as a great media. It has gotten rather expensive but I found a cheap source and now have more than i'll ever need:
tree fern fiber

just go over to the menu on the left

[kindrag23]

Originally Posted by Cactuseed

I second tree fern fiber as a great media. It has gotten rather expensive but I found a cheap source and now have more than i'll ever need:
tree fern fiber

just go over to the menu on the left

I just found today that the bark media is staying WAY to wet; in my greenhouse environment. I have almost lost my oncidium wild cat, it has 3 large sized new growths. Thank goodness!! I have moved it to lava rock. I will most likely be moving the others rather quickly as well.

---------- Post added at 09:27 PM ---------- Previous post was at 09:22 PM ----------

I also did not have time to water for 4 days and it was still really wet in the bottom/ lower half. And I only lightly/medium water w a sprayer in my greenhouse. Every 3 days. This was also after 3 days of pretty nice weather upper 70's outside so 80*'s in the greenhouse with high humidity.... lava rock seems to be the way to go...

[Leafmite]

Yeah, I went to lava rock for multiple reasons.
1) never decomposes so I never need to worry that the bark in the middle is tightly packed and staying wet
2) I don't need to spend a bunch of money each spring replacing the bark
3) I can water like crazy and the roots are still happy (with the net/basket pots)
4) I don't need to disturb the roots of my orchids every year so I have better blooming
5) I can recycle the lava rock when I repot by baking or boiling it
6) It is so much cheaper ($6) than bark to buy and one large bag lasts a long time.
7) Ants don't make nests in it
8) It will wick up water
9) Weights down the pots so they don't blow around in storms or fall over from the weight of the flowers

I can probably think of more if I try harder but, yes, I really love the red lava rock.
One thing I have discovered is that it helps to use eggshell or some other source of calcium as that seems to wash away very easily. I've never had fertilizer salts build up on my rock but I use lower amounts of fertilizer. Good luck! I've been growing in it for many years and it is my absolute favorite medium.

---------- Post added at 11:07 PM ---------- Previous post was at 11:02 PM ----------

10) keeps a humid environment around the roots without staying too wet. Also provides humidity to the orchid as the water evaporates.

[AussieVanda]

Hi kindra, I've found that oncidium will grow on mostly anything providing that the media is relatively free draining. Slabs, tree trunks etc all work fine. At the moment I have a big bunch of the stuff growing around the base of a potted plumeria with 4 spikes in flower and just for kicks I threw a couple of bulbs inside a cement block in mostly full sun with no media other than the block and the dirt it sits on. The older growth suffered but now it has new bulbs which are doing fine.

I guess my point is, is to be creative and experiment. Never know KindraG, you may be the next 'trend-setter' on OB!

[katrina]

Been using leca and/or lava rock for 3 or 4 years now...love it for anything that wants/needs to drain quickly and dry out between waterings.

For oncids, I prefer shredded redwood. For me the lava would dry out too quickly for water hog Oncids. But, that's just my grow space.

Another interesting medium you might want to check out is ...Grow Stones. I recently started using this product...it holds a bit more moisture than leca or lava and early results look like it'll be a good one for those plants that need a bit more moisture than catts. It's very light weight though..might not work out well for tall oncids.