How does an orchid "know" that it is pot bound?

[bil]

Originally Posted by gnathaniel

Sorry, gotta disagree, you're waay over-generalizing the vast diversity of epiphytes, including Orchidaceae and multiple other species-rich families. Many epiphytes and lithophytes do show remarkable preference for confined spaces like hollows and crotches in trees, arboreal ant nests, leaf/frond axils of bromeliads and ferns, tight rock crevices, etc. Likewise some orchids do best for me in narrow, tall pots, others in broad, shallow dishes without drainage, or on various types of mounts, etc etc...

Well, of course we should add the caveat that there is no the slightest guarantee that what works for me, or for you will work for anyone else.

Second, seeds will most usually settle and germinate in a crevice, so few plants will grow on plane surfaces. Lithophytes, not my field, but I find it hard to imagine one that wasn't stuck in a crack.

Generalisations work just fine, as long as you realise that's what they are.

[astrid]

Originally Posted by gnathaniel

Astrid, are you asking about a specific type of orchid? As posed, your question is too global for a coherent answer, perhaps because you start with the over-general and not universally true assumption that 'orchids thrive when potbound' (some DO seem to, others not). Not trying to be rude; if more specific you pose an interesting question, but as with most things orchid culture it's rarely accurate or useful to speak in broad generalities.

Nope. I just read that "X orchid LOVES to be pot bound" and "Y orchid really loves wearing 'tight shoes' " and "Z orchid only thrives when the pot is bursting in a giant root ball."

And I am curious why people say that and how could a plant "know" if it was pot bound or not. My hypothesis after this discussion is (1) Orchids love stability and will thrive when stable so (2) orchids that are pot bound are very stable indeed also (3) with a huge root ball, there is little media around to stay constantly wet so they are less likely to have any rotting issues.

[bil]

Originally Posted by astrid

Nope. I just read that "X orchid LOVES to be pot bound" and "Y orchid really loves wearing 'tight shoes' " and "Z orchid only thrives when the pot is bursting in a giant root ball."

And I am curious why people say that and how could a plant "know" if it was pot bound or not. My hypothesis after this discussion is (1) Orchids love stability and will thrive when stable so (2) orchids that are pot bound are very stable indeed also (3) with a huge root ball, there is little media around to stay constantly wet so they are less likely to have any rotting issues.

WRTo 3, surely a compacted ball of roots is likely to suffer from suffocation?

[NYCorchidman]

A few great points have been made here.
Let me just add a few things.

First thing first, potbound plants thriving, whoever started saying it, is nonsense. It is one of those things that just float around. Someone said it, heard it, and then just pass it on whether it be online forum or magazine or book...I just hate seeing it all the time still. How annoying!

Especially epiphytes that grow their roots freely all over the tree trunk, there are no bound!

Two, environmental stress causing plants to flower, I find this as a mystery as well. At least temperature.
Drop in temperature helping certain plants to flower is not because the cold shocked or stressed the plant, but certain plants require that drop in temperature at certain time of the year (or depending on the plant, any time of the year) in order to flower the following season, also to stay alive. These plant won't stay healthy for long without proper "winter".

Also, as Camille kindly shared the info, if you were to have a bigger plant, the plant must have bigger root mass to sustain the above the root portion.
Think of bonsai. Or try growing plants very crowded. They will stay quite small or some of them will just die off. Then transplant them into larger pot on their own. You will see a big jump in no time for annuals and other fast growing plants, and a bit more time in orchids but you will see it.

And roots or plants, they know what environment they are in. I find this very very fascinating!

[lotis146]

I've been hearing that they like to be somewhat pot-bound since day one, so it's quite interesting to understand that that's not exactly true. Now I see that like with so many other things it all depends on multiple variables. But it would seem at the end of the day that it can be dangerous to say they thrive on being pot bound as eventually the plant will not have the space available to grow more roots. I would ask, is it important to getting a plant started for it to be somewhat pot bound?

[bil]

What does a plant need from its roos? Ignoring support for a moment, it gets water, nutrients and so on.

Look at it logically. If the roots are so tightly packed that no water or nutrients can get in, the root will be less than functional, and if the air can't get in, it will also be dead.

If epiphytes only liked close confinement, then their roots would hardly spread out far and wide.

In short, there are a number of statements made about orchids that are counterintuitive. Tight roots and wetting the crown being the two that spring to mind.

There may be species of orchid that DO like tight confinement. That would be interesting to see if anyone does have such orchids in mind. However, at the risk of making a generalisation, for the average orchid keeper, I think it is safe to say that the less an epiphyte's roots are constricted, the better.

[lotis146]

What I'm going after in asking my question is that I have heard some orchids (wish I could be more specific) do not do well if they are 'unstable' in the pot. For instance I have bought plants (online) that arrived in coconut choir which I've found by itself to not be so great for smaller plants without some kind of support. According to what I've heard in the past here such a plant may not grow as fast b/c it's so wobbly in its pot. Thus I ask if with smaller (younger) plants they do well starting out if they have a 'good grip' so to speak on their surroundings?

If makes sense to me that they would because in the wild the plant grows from seed to seedling establishing itself and sending out roots, gaining a firmer hold with each new root and new inch gained. Of course like most natural things they want to be able to spread out so confining it to small spaces for its life I don't believe to be ideal but could it be that this rumor starts out with us growers needing to be able to stabilize our plants and care for them properly until we and they are thriving. If the error never gets corrected than we never expand our experiences to growing in bigger pots...

Certainly people who grow their orchids outdoors on trees do not confine their plants... I would bet people have had rave success keeping plants pot bound b/c they find watering easier so this successful person then passes on their knowledge and... Perhaps it would be a wonderful challenge and experiment for all willing to take a plant we're quite comfortable with and repot it bigger than is recommended (next time it needs repot) while taking medium drying time into account and just letting it be free!!!

[bil]

Experimentation is the key to find what works best for you.
I think that if an orchid is healthy, and is kept under the right conditions, it will shrug off stuff that would kill it were it weak.

Outside in the wild, every time there is a cool night, and there is mist in the morning, that plant is going to be saturated.

To give you an idea of how penetrative that mist is, I can't use battery powered digital max/min thermometers outside hhere. If I do, cool mornings with mist send moisture right into the electronics and shorts them out.

[NYCorchidman]

Originally Posted by bil

What does a plant need from its roos? Ignoring support for a moment, it gets water, nutrients and so on.

Look at it logically. If the roots are so tightly packed that no water or nutrients can get in, the root will be less than functional, and if the air can't get in, it will also be dead.

If epiphytes only liked close confinement, then their roots would hardly spread out far and wide.

In short, there are a number of statements made about orchids that are counterintuitive. Tight roots and wetting the crown being the two that spring to mind.

There may be species of orchid that DO like tight confinement. That would be interesting to see if anyone does have such orchids in mind. However, at the risk of making a generalisation, for the average orchid keeper, I think it is safe to say that the less an epiphyte's roots are constricted, the better.

Yes, and that's why greenhouse growers who pot things like cattleyas and oncidiums among other things, in large slab with long lasting mix that does not need repotting for a very long time, enjoy having huge & happy speciemen sized plants. Or even better, people in the tropics who grow orchids on their trees, just like they would in the wild. Sigh~

---------- Post added at 04:15 PM ---------- Previous post was at 04:07 PM ----------

Originally Posted by bil

Experimentation is the key to find what works best for you.
I think that if an orchid is healthy, and is kept under the right conditions, it will shrug off stuff that would kill it were it weak.

Outside in the wild, every time there is a cool night, and there is mist in the morning, that plant is going to be saturated.

To give you an idea of how penetrative that mist is, I can't use battery powered digital max/min thermometers outside hhere. If I do, cool mornings with mist send moisture right into the electronics and shorts them out.

I also agree with this.
Wetting the plants does not make them spotty or get sudden rot. Disease occur because the growing conditions are not very good and/or plants are just too weak and meant to be doomed. lol

I had oncidiums (many of them are notorious for spots and marks, hence I do not deal with them any more) that I never misted its leaves. They still developed plenty spots and marks.
Then there were certain oncidiums that I always misted and showered, and never had a single tiny spot ever!

I do think however, for plants like phalaenopsis, having water sit on the crown can lead to a problem, although I don't know how true it is (most likely not true hahaha), who wants to experiment with their baby? haha
Wild phalaenopsis grow vertically with their leaves dangling down, so the crown is always facing sideway and water will never sit on the crown. Maybe this is why some people started saying having water on the crown causes crown rot.

There are other environmental factors as well. In the wild, there might be better balance between microorganisms that keep the pathogenic ones population in check. Plus, as soon as the sun rises, the warmth and all the breeze might just dry the plants up quite fast.
And not to mention, in a great growing condition, plants might just be much stronger to fight off invading organisms.

[bil]

Originally Posted by NYCorchidman

Disease occur because the growing conditions are not very good and/or plants are just too weak and meant to be doomed. lol



I do think however, for plants like phalaenopsis, having water sit on the crown can lead to a problem, although I don't know how true it is (most likely not true hahaha), who wants to experiment with their baby? haha
Wild phalaenopsis grow vertically with their leaves dangling down, so the crown is always facing sideway and water will never sit on the crown. Maybe this is why some people started saying having water on the crown causes crown rot.

There are other environmental factors as well. In the wild, there might be better balance between microorganisms that keep the pathogenic ones population in check. Plus, as soon as the sun rises, the warmth and all the breeze might just dry the plants up quite fast.
And not to mention, in a great growing condition, plants might just be much stronger to fight off invading organisms.

Me. I am sadistic and cruel enough to experiment. I make sure that I ALWAYS wet the crown. Wet it? I fill it. EVERY SINGLE TIME. The only one I have lost from crown rot was one among 6 who were a bit too cold, and who were watered very carefully. I was concerned about them so I kept them as dry as poss. They NEVER had a wet crown.

In addition, I have never found a phal that will hold water. I fill the crowns, they drain out.

In the wild, the crowns will get wet, as mist gets everywhere. I don't water after a certain time, because in the wild I figure they dry out before nightfall usually, and I don't think cold and wet is good. I think it's the cold that does the damage, but moisture will 'up' the chill factor and perhaps push the plant over the edge.