I'm confused about air roots!

[Dr. Dave 4u]

Hi all..
seems everyone is an expert on the internet and I am finding conflicting information...so whats new?!!

-I am wondering if one pots up a keiki with long air roots does one put these into the loose breathable medium? If not how do you anchor it in the pot of leave it floating on top of the medium?

-When one repots a mature orchid with air roots do you always leave them out or can some go into the medium?

-If you break an air root when trying to get it into the pot will that root still be viable?

I had read that air roots are different than roots that grow in the medium and some experts/people say they are not good for the other purpose.
Thanks for the help!

[Dusty Ol' Man]

Someone will correct me if I miss this one, but roots from a keike are not really air roots. The new plant is looking for moisture with these roots. If/when this growth is potted, put the roots into the medium like any other main roots. Sometimes it is necessary to support the plant to prevent movement until the roots establish themselves in the medium.
Air roots on a mature plant can be left above the medium. I would give them a spray everyday, depending on your conditions.
As far as breaking roots goes, I can't answer that.
Good luck with your plants and don't hesitate to show your results.

[SouthPark]

People are the ones that choose names and words for things. 'Aerial' roots just mean roots that grew out into the open ------ open air that is.

Roots ('aerial' or otherwise) can actually develop root nodes along the length of the original root ------ from which a branch root can grow out from. So even if you do happen to break a long root along the length ------ it doesn't necessarily mean the whole root will be out of action. Even a busted root can keep functioning.

I manually shove 'aerial' roots into pots as well. I try to keep roots unbroken if possible, but I know that everything is going to be just fine even if some become broken along their length.

One handy thing to know is that roots require enough oxygen to survive. And roots that have 'adapted' to relatively low oxygen environments (such as soggy, damp, or watery, or water) can generally handle those environments ------ while regular unadapted roots that are growing in the air or in regular media will probably not survive for long in long-time wet/watery/low oxygen environments ----- as their cells haven't been adapted or configured for those conditions.

And adapting to those conditions (I think) generally requires the roots to grow into a particular medium - and the cells adapt. But abrupt potting of regular roots into long-term watery conditions, or relatively long-term soggy media conditions generally has a bad outcome.

It's ok to put air-roots into media ------ provided we control the amount of moisture (water) in the media (in the various regions and depths of the media) and on/around those roots. And also have the temperature around the roots in satisfactory ranges.

[Orchidtinkerer]

Roots are roots whether they grow into some substrate or not.
Consider that not everyone pots up their orchids, some like to keep them bareroot. What are the roots then? Simple they are still the same roots.
If you want to call your tv dish an aerial it is still performing the same function. Same with roots that grow into the air.

I find calling them aerial roots is just misleading and confusing as the roots haven't changed so why change the name.

I once had a leaf grow into the pot instead of the air, would that then suddenly turn the other leaves into aerial leaves

If someone tries to tell me my jeans are no longer called jeans, they are now called legoveralls, I won't consider them an expert, I'd consider them something else. When it comes to orchids, few people know any better so just accept any latest theory. I am far from an expert but I know enough to know the experts are too busy growing and breeding orchids to be frequenting this forum.

I should point out one last point about orchid roots and why the term aerial root even started, orchid roots are not like regular houseplant roots , regular houseplant roots if exposed to air dry up. Orchid roots have a thick velamen protecting them so they have adapted to be able to be exposed to air without drying up like other roots would. Hence aerial roots - as in roots that can survive in air. And thats all there is to it.

[Clawhammer]

Originally Posted by Orchidtinkerer

Roots are roots whether they grow into some substrate or not.
Consider that not everyone pots up their orchids, some like to keep them bareroot. What are the roots then? Simple they are still the same roots.
If you want to call your tv dish an aerial it is still performing the same function. Same with roots that grow into the air.

I find calling them aerial roots is just misleading and confusing as the roots haven't changed so why change the name.

I once had a leaf grow into the pot instead of the air, would that then suddenly turn the other leaves into aerial leaves

If someone tries to tell me my jeans are no longer called jeans, they are now called legoveralls, I won't consider them an expert, I'd consider them something else. When it comes to orchids, few people know any better so just accept any latest theory. I am far from an expert but I know enough to know the experts are too busy growing and breeding orchids to be frequenting this forum.

I should point out one last point about orchid roots and why the term aerial root even started, orchid roots are not like regular houseplant roots , regular houseplant roots if exposed to air dry up. Orchid roots have a thick velamen protecting them so they have adapted to be able to be exposed to air without drying up like other roots would. Hence aerial roots - as in roots that can survive in air. And thats all there is to it.

Roots adapt to the environment they grow into, so all roots are not created equal. Roots that grow into the air require a lot of air, and in my experience get suffocated quite quickly if jammed in a medium with less airflow and a different pH.

Vice versa, if you were to unpot a plant that grew into sphagnum and mount it, those roots would likely desiccate promptly, much quicker than aerial roots.

[Roberta]

Often, a Phalaenopsis in particular will send out a lot of air roots if the medium is bad - these, and the roots of other epiphytes, have evolved to need lots of air - really wanting "humid air" rather than "wet". However, roots WILL somewhat adapt to the medium that they are growing in. Clawhammer is correct in noting that drastically changing the environment of existing roots is likely to kill them. That's why the ideal time to pot any orchid is just as it is starting new roots - the new roots will grow into the new medium. Now, Phalaenopsis are growing and rooting pretty much all the time, so timing isn't so important. If you have lots of air roots on a Phal and want to move them down into the medium, they'll be fine, and appreciate the extra moisture. If the bottom part of the plant is mostly dead from soggy medium, it's also a good time to clean it up - if it has new roots, it won't miss the old bad ones. But then, pot it into a medium that is open and airy... then the new roots will get the best of both worlds - air but also the moisture that they likely aren't getting when they're completely in the air. Also, when you water, water well - so that water runs out of the pot. That flushes "crud" and also pulls air into the roots zone.

[Ray]

Back in 1998, I was having a similar discussion with Rod Venger (late, of Venger's Orchids in Colorado Springs). I was working on S/H culture, he had just originated water culture, and we were comparing notes.

He had a friend, Robert Lin, working on his PhD at Texas A&M (I think), and asked him about root adaptation to water culture. His reply, below, can be broadened to roots in all growing situations:

You have asked a very difficult question to answer without writing a small book. To give you a generic short answer for others to understand, I must first qualify my statement before I make it. All of my information is based on other people's publications. My answer is based on what I've read and the answer is not exclusively true for all orchids as some have very different root structures based on their unique development and adaptive needs.

First, orchid roots function to uptake water and nutrients, preserve water loss during drought conditions, and also allows the exchange of gases to regulate life cycles. Root structures (i.e., cellular shapes, sizes, types, and the number of cells from the cortex to the velamen) will vary from species to species and maybe from plant to plant depending on what and where it is growing. For this and many other reasons, orchids (and other plants) are highly adaptive to changing/varying environments.

Many people have reported that orchid roots develop differently depending on the surface it comes in contact with (i.e., its environment) as it is growing. Roots can grow fully exposed dangling in the air, in contact partially on a surface (e.g., bark), and/or growing in a "soil" medium. When an aerial root touches a surface, the portion that comes in contact with the surface will adapt differently so that the cellular function is optimized for the plant survival. For example, the area that contacts a piece of bark will often develop roots hairs on the bottom side, together with smaller velamen cells and thin walled passage cells. This will help an orchid cling to the bark and allow better transfer of water and air on the bottom side as it grows attached. On the exposed side, passage cells become more lignified or suberized for protection and reduces water loss in the air. Roots growing in "soil" can develop a modified velamen layer but do not always do so like roots exposed to to the air.

If roots grow into water, they will adapt to regulate water passage with specialized cell development for a water environment. Established aerial roots placed into water (as compared to new roots that grow in water) usually survive and can adapt because aerial roots have outer cells that are structured to not allow water freely into the plant (but can still regulate gas exchange). This allows time (maybe 3-6 months) for an orchid to readapt and grow water roots in the new water environment. Some aerial roots will rot soon after being placed into water but this can be attributed to physical damage that occurred before being placed in water. A crack along any part of the root will allow water (and therefore fungus/bacteria) into the unprotected center of the root and rot occurs. Some aerial roots just can not adapt to water conditions and die off, but hopefully
new water roots have developed by that time.

In general, water roots, aerial roots (attached and unattached), and "soil" roots are different because the roots have developed differently to optimize and regulate their growing condition. Orchid roots adapt by developing specialized cells based on the surface it touches (environment it is in), so each root can be structurally and functionally different from one another. An orchid will try to adapt physically, chemically, and biologically to an environment to ultimately produce offspring.

[SouthPark]

Also ------- I think that 'water roots' ------ if re-conditioned satisfactorily ------ can survive in regular media (air/rocks/bark etc) right?

I did mention sometime ago on OrchidBoard that ----- one of my catts grew roots that extended out of the bottom of the pot and into sandy soil and built up a large unseen clump of roots underneath the surface of the sand/soil. Not deep into the soil though - just under the surface. They had no problem growing there.

[aliceinwl]

I have seen different root morphologies depending on whether the root is growing in the air or in the substrate, but the roots don’t seem to be locked in. I’ve had a few Phalaenopsis I’ve repotted with extensive air roots but no roots in the substrate. I had no root death after burying the air roots and a few months in, the roots look nothing like the air roots I buried.