Encyclia cordigera: New growths develop no roots, change potting?

[Orchid Whisperer]

I have an E. cordigera that I have had for 3 + years. It bloomed the first year I had it, skipped a year, and bloomed last year, nice show, but not spectacular.

Currently it is in a terracotta pot, mostly in lava rock (maybe 70 - 80%) with a little charcoal and coarse fir bark.

The original plant had one large pseuobulb, green, glossy and the size of a medium onion (roughly 1.5 to 2 inch diameter), and some smaller older pseudobulbs.

The plant has added only two pseudobulbs since I purchased it, about one every other year. Significantly smaller (1 inch) than the large one I mentioned. No new growth this year. Added later, photos:








Neither of the newer pseudobulbs has ever had a new root develop. Not a single root, not even a nub, no indication that a root was created but later eaten by pests. The youngest of the 2 newer pseuobulbs bloomed last year. The plant is clearly still absorbing water, leaves seem fine, pseudobulbs still shiny, including the old pseudobulb. The 2 new growths both came from the older pseudobulb.

My understanding is that E. cordigera can be picky about potting. Should the current potting media/pot be suitable for it? Should I consider mounting or placing in a wood basket in the future, no medium? Over the winter, I have considered shaking any loose medium out of the pot and seeing if the plant makes any new roots.

I would appreciate advice from anyone that has successfully gotten this species to grow and produce new roots and growths. What should my next move be?

Thanks.

[Leafmite]

One thing to remember about rock is that it is hard and, sometimes, sharp, and it can discourage roots if the rock scrapes against the area from which the roots emerge. Until the orchid is established in the red lava rock, it is important not to move the pot around or, if you must move it around, to put a thin layer of NZ moss under the base of the new growth to protect it. I use air tubing (from my fish hobby days) to drain trays and saucers so I do not need to move the pots when I have new growth. Staking an orchid on top of the medium and letting the roots grow down into the medium is another trick I use. The area from where the roots come is slightly above the medium so that it cannot rub against the rock. I still try not to move the orchid. Once the roots hold the orchid steady, it is safe to move them.
Lastly, with rock, it is very important to flush the rock often to prevent fertilizer and minerals from accumulating and harming new roots. New roots will not grow if the rock is not the right pH or too salty.

The other thought I have: Try a liquid seaweed additive when the new pseudobulb begins. When I bought an Angraecum with all dead roots, I went with a liquid seaweed plant additive. The effect was quite amazing. I found that it helps to look for one with a five-star rating on Amazon and, in the reviews, make sure that people have used the product at least one full season.

[Bohata]

I second the seaweed, if that seems to have sensible scientific support. Forgive the alliteration. I get carried away.

[Orchid Whisperer]

Originally Posted by Leafmite

One thing to remember about rock is that it is hard and, sometimes, sharp, and it can discourage roots if the rock scrapes against the area from which the roots emerge. Until the orchid is established in the red lava rock, it is important not to move the pot around or, if you must move it around, to put a thin layer of NZ moss under the base of the new growth to protect it. I use air tubing (from my fish hobby days) to drain trays and saucers so I do not need to move the pots when I have new growth. Staking an orchid on top of the medium and letting the roots grow down into the medium is another trick I use. The area from where the roots come is slightly above the medium so that it cannot rub against the rock. I still try not to move the orchid. Once the roots hold the orchid steady, it is safe to move them.
Lastly, with rock, it is very important to flush the rock often to prevent fertilizer and minerals from accumulating and harming new roots. New roots will not grow if the rock is not the right pH or too salty.

The other thought I have: Try a liquid seaweed additive when the new pseudobulb begins. When I bought an Angraecum with all dead roots, I went with a liquid seaweed plant additive. The effect was quite amazing. I found that it helps to look for one with a five-star rating on Amazon and, in the reviews, make sure that people have used the product at least one full season.

Added some photos.

Thanks for the suggestions.

As you can see, it is in black lava rock (which has worked well with other Encyclias and hybrids that I have). The roots from the older pseudobulbs are pretty well attached to the rock and the pot, so I don't think wiggling and scraping roots against the rock is the issue. Also, there is never any indication that the roots even attempt to grow. It is as if the plant has forgotten how to even try to grow roots!

In winter, I use stored rain water for watering, fertilize rarely, and in warm weather the plants are outdoors, usually experience good natural rainfall. At other times, I water with tap water, here it is TDS in the low 100 ppm range or sometimes high double digits. So, plants should get a good flushing.

I have used kelp extract on this plant in the past. That has worked well on other plants that have some root development, the new growths on this plant never initiate any new root tissue. I will try the seaweed again if it ever develops more pseudobulbs.

[Ray]

OW,

It could be that you're keeping the medium too dry, but that's just a guess.

If you are willing to unpot and repot the plant, or can figure a way to anchor it and the medium in the pot, immerse it for several hours in a kelp solution.

(You know I'm going to recommend KelpMax, as it is better than any stimulant I've ever seen, and I've experimented with synthetic and natural ones for 45 years. And... it is currently on sale, with free shipping, and I'm donating $5/L to Hurricane Harvey relief.)

[Leafmite]

As it is well anchored by roots, just soak the entire thing in a bowl of either a solution found on Amazon or KelpMax. In this case, I do not think it is wise to disturb the old roots. Good luck!

[estación seca]

I have a seedling in S/H. My experience is it needs a LOT of water. In your potting medium I would feel compelled to water every day.

Also, your plant doesn't look to me as though it is getting enough light.

The new growths on my plant make roots after they are nearly mature.