That's probably true. People can have difference of opinion, and I still see this as a case of logical fallacy.


Funny thing is, we also have a difference of opinion on this unless you're saying that root bound and pot bound are different terms. While I do agree that being pot bound is good for stability, I also know at least in my collection, that plants are and can be stable in their pot well before they reach the point of being pot bound. Now if your saying root bound is different than pot bound, I guess the point is moot, though I did think the conversation was about orchids being pot bound.

That's the thing with language and communications heheh. It's all about definitions. Such as - the terminology 'pot bound' can very easily be interpreted (or mis-interpreted) as confined within the boundaries of a pot - not necessarily having filled all or most of the available free space in the pot. But the definition in dictionaries makes it the same as (or along the lines of) the terminology 'root bound' (filled to capacity or almost to full capacity). Or basically, a dense root system has formed taking on the shape of the pot.

If the plant is not "potbound" ... pot stuffed with roots... the determination of whether this is good or bad is, at least in part, a question of what ELSE is in the pot... if it's in an inorganic (or mostly inorganic) medium so that there is air in the middle of the pot (water drains freely and leaves humid air behind) the orchid is getting what it needs and pot size isn't important. It's growing more like a mounted plant. However, if the medium in the middle of the pot stays wet and airless, not good. And as pot diameter goes up, the volume increases faster (square vs cube of the diameter) so getting that air exchange in the middle of the pot becomes a challenge. One way of getting the pot diameter up without creating a "dead air" pocket is to invert a pot in the middle to prevent it filling with medium. But that's where the "don't overpot" advice comes from. Also, this varies with type of orchid... put a Cymbidium in a pot with extra growing room, it will mostly produce roots and leaves. When it gets to the point where it is ready to break the pot, that's when you get good flowering. Possibly the stress drives the flowering response.

that makes a ton of sense Roberta

Pot bound = conditions where an orchid is watered well but the roots always have access to air. Medium should dry rather quickly (allowing the air access). If you have too much medium that easily becomes compressed, you do not get air to the roots and the roots will suffer and decompose. With bark/NZ moss and a solid plastic pot, you have these problems. With a basket pot and red lava rock/limestone, these problems will never exist and the size of the pot does not matter.

Thanks leafmite.

I think it is a term that is casually used and has different meanings in different applications. Orchids vs standard terrestrials in top soil etc

I have always used potbound and rootbound synonymously. "Needs to be repotted when next growths emerge".

So what I'm getting from this discussion is that it's not that orchids like to be root bound, it's that root bound orchids are grown in conditions that it likes. So a reverse of cause and effect.

However, it's still a question whether the actual root bound effect is positive. I wonder.

I think the benefit, or not, of the rootbound effect varies. For Cymbidiums, it definitely helps - they bloom best just before they break the pot. (As long as they have extra room, they tend to do more in the way of roots and leaves, less flowers. I think most of us grow them for the flowers) Other genera, probably not so much... getting the air into the root zone is what is critical, and with some potting media that can be achieved in a larger pot... but for bark, an oversized pot leaves a "dead zone" in the middle, not good.

That's interesting and I think it integrates well with my thoughts. For most orchid growers, blooms seem to be the metric for plant health. The plants probably prefer to spread out their roots and grow more leaves. They're like an energy investment. Perhaps the root bound condition tells them they're out of room and it's time to send out seed to make progeny. If someone says a plant likes to be root bound to trigger flowering, as opposed to that plants like to be root bound to be healthy, I would be much more ready to accept it. It's just unintuitive to me if more space actually harms plants (in itself, I get your concern about wet spots in the center of a bark mix).