Air Roots Shriveling
 

Hello,

I have about twenty Phals in my collection. I have noticed lately that I am getting good strong roots that develop either just above the potting medium or out of one of the side holes in an "orchid pot". These roots look strong and thick and green. After a few weeks, they usually turn gray and then eventually shrivel up. Am I doing something wrong? The RH is always above 50% and closer to 60% usually. I am underwatering? Should I try to cover these roots up with sphag? Please help.

Thanks,

John

Do they get soft before they shrivel up or just start to get wrinkly? How is the plant doing otherwise?

In addition, how often do you change out the media?

What's your fertilizing regimen?

I put sphag on top of the medium, and cover roots that appear above the sphag with more sphag. Works for me.

I mist most of my aerial roots and they seem to like it

I do the same, I also try and make sure they get water from the tap poor over them when I water.

The plants are otherwise fine and not in need of repotting. I guess I should start misting the roots in the morning. Also, I like the idea of placing moist sphag on top. Thanks for the suggestions.

They're just drying up because they're not getting any water. I wouldn't bother trying to look after them by extra misting, watering is what the media should be doing for you - you didn't go to the trouble of putting an orchid into a pot just so you could mist it every day like a vanda.

What do you mean by 'not in need of repotting'? Phals rarely -need- repotting like other orchids that grow offsets and have tonnes of roots and run out of room. But they do get tall and start growing new roots over the media that shrivel and die and that's when they need repotting, or at least repotting deeper down into the pot.

And yes i would use good quality sphagnum as a general rule with Phals. In a medium that they're used to that holds a lot of water they will tend to grow larger forking root systems in the media itself rather than send roots up searching for water.

When was the last time you repotted? If the media is breaking down and getting acidic, the roots shrivel too. It's not just a water problem.

If you're over fertilizing, Phals don't get leaf tip burn, they'll show you there're excess salts via their roots shriveling.

If you're not watering often enough, Phal roots shrivel.

If the roots are not being provided enough humidity, they shrivel.

If the roots are not in contact with anything in the long run, they run the risk of shriveling (not all orchids have an issue with dangling aerial roots that attach to nothing, and it depends on the environment too).

If the roots have been given salts they can't process, the roots start shriveling.

If the roots are used to one type of environment and moved to another that it can't adjust to, yes you guessed it, the roots shrivel.

You see how complicated this issue is? It's not so simple, but the same problem arises in the multitude of scenarios I just provided. I've messed up many Phals in the process to learning what I've done wrong, and what is acceptable and what isn't.

Just to give you an idea, I have a Thrixspermum centipedum do the same thing. It was growing two new aerial roots (woohoo!!!). Then all of a sudden they shriveled (what the...???). I watered this thing every day. I fertilize infrequently and in small concentrations with a non-urea based fertilizer. What was the problem? They were growing fine.

Guess what, I hadn't changed out the moss on the mount in ages (2 or 3 yrs not sure which). And I conducted an experiment that did more damage than good (I used a dilute synthetic saltwater mix to provide the macro and micro-nutrients I thought it might be missing - total bomb). And the aerial roots were just dangling in mid-air for quite a while (about a month or so) almost about to touch the mount itself too (doh!). To this day I can't isolate a singular factor that caused the problem. It's too complex (mostly my fault). I adjusted from this, and...as an added bonus, I figured maybe it grows in a pendulous manner instead of upright, so why don't I grow it pendulous so that it doesn't have a hard time trying to get its internal juices to where it needs to be by fighting against gravity.

That's why I'm asking these seemingly asinine questions.

Given they're just the aerial roots I don't think the shrivelling is anything too complicated.