Why are all Roots on Big Cattleyas Dead?

[thefish1337]

Originally Posted by itzi

When you say different ceramics, do you mean the orange clay pots that you can get from garden stores, and they all have different compositions? Or something else?

I'm too lazy to take pictures right now but I'll post pictures tomorrow. Most garden stores around me sell "Italian" terracotta which has smaller pores and is more dense. I have some other super porous terracotta/clay pots from japan for growing neofinetia. I also ordered some terracotta from amazon clearly of chinese origin which is intermediate to the two types.

[itzi]

Oh wow! I had no idea that the porosity could be different depending on the pot. Is there a way to tell just by looking at it?

[estación seca]

Try just one big Catt in LECA.

[Ray]

Originally Posted by realoldbeachbum

Thanks, Ray. Based on your input, it must be a watering issue.

Most of the evaporation from the pot occurs at the top surface and the interface between the medium and the pot wall (yes, even plastic, as the media particles up against the "flat" surface is more open than with the body of the medium). That typically leaves a soppy, stagnant "pocket" right in the middle of the root mass.

Don't write it off 100% to that, though. When you move a plant to a bigger container, the existing roots (not optimized for the new conditions) will be in the middle, and new roots will tend to grow around the pot wall for stability.

Originally Posted by itzi

When you say different ceramics, do you mean the orange clay pots that you can get from garden stores, and they all have different compositions? Or something else?

There is a great deal of variation in the formulations used to make a "clay" pot - different types of clay, additives, etc., and how they are fired also plays a role in the final porosity. Fine china starts as a clay-based body, but with the proper firing cycle, it all becomes vitrified (i.e., turned to glass).

Originally Posted by itzi

Oh wow! I had no idea that the porosity could be different depending on the pot. Is there a way to tell just by looking at it?

Yes, there is potentially some visual difference, but that is usually not sufficient to discern a difference.

One of the best ways to judge is to touch your moist tongue to the surface - the more it absorbs and "tighter" it grabs your tongue, the more porous - but I don't recommend that. Instead, moisten a fingertip and touch the pot. It's not as sensitive, but far more sanitary!

[Paphluvr]

Originally Posted by realoldbeachbum

[/COLOR]Thanks, Paphluvr! I didn't even think of media being too small and retaining more water. It is 3/8" Orchiata with a little charcoal mixed in. No spagh. Thoughts?[COLOR="Silver"]

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I don't use orchiata so I don't know what sizes it comes in, but in general would consider 3/8" too small for Catts. How irregular are the pieces? Depending on your humidity and watering habits I would think something on the order of 5/8 - 3/4" would be more suitable.

[isurus79]

I'll also chime in and say that if a basket dries too quickly, then clay pots are your best bet. Paphluvr is also correct with increasing the orchiata size for mature plants. I use the largest size I can buy for my Catts, ideally the 1" size. However, sometimes only the 3/4 to 1" size is available, which is good as well.

[Clawhammer]

I used to despise the white build up on terra cotta, now I find it kind of elegant looking, like a patina on old wood.

Not sure that adds anything to the conversation lol.

[Steve83]

Its' just natural senescence of old roots, attached to old pseudobulbs.

Mounted plants do the same thing.

[Fairorchids]

Most Cattleyas will run their roots across the surface, and around the outside of the mix. You will hardly ever find roots in the center.

So, if you have some roots across the top and around the inside of the pot, the plant is perfectly healthy.

[SouthPark]

One thing we can do is to look at the roots and the media within the pots ----- during unpot and repot times.

Assuming we had been more or less keeping to our own watering schedule --- and not doing the unpotting when the media has dried right out ------ then we can usually get some idea about whether the media and roots are ok or not. For example ----- when unpotting --- if the mass of roots right underneath the orchid are dead --- down in the dark depths of the pot, then see if the roots are very wet and soggy/soppy, and if the media is saturated/soggy/soppy --- or even slurry-like.

If conditions like that stay the same for a long time, then root drowning can occur.

If the orchid keeps growing roots -- new roots around the outside of the dead bunch of roots at the centre ----- then that should be ok --- as long as those new roots on the outside have no issues with staying alive.