"Likes a lot of air flow"- what's this _really_ mean?
 

"X plant wants a lot of air flow"

"Give it a lot of fresh air"

What's this really mean? They can't possibly suck down enough c02 to need more all the time, right?

Does it maybe mean they're easily susceptible to rot and can't stay wet for too long?

IME, a lot of air flow fends off mold in high humidity conditions. Is that it?

What's the wisdom behind this advice?

Thanks

It means a tightly enclosed, humid space is a problem. Even at high humidity a small fan circulating the air may prevent fungal infections. On most windowsills there's plenty of air circulatipn without a fan. Fans might also be useful preventing leaf overheating.

Remember that most of the orchids that we grow are epiphytes - they grow on the sides or branches of trees. It rains, and then the breeze dries them. So orchid roots need "humid air" more than "wet". That's why they need a medium that has lots of air space - whether bark, or sphagnum, or the various inorganic media, the common denominator is air. When you water, do it so that water runs out of the pot - that pulls air into the root zone. As the water evaporates, it is replace by air. Mounted orchids grow with their roots in the air, and if you have the humidity that they also need, that's the closest to what they'd get in nature. For most of us, to maintain the humidity they need to be in pots, but the need for air in the root zone is still vital.

I agreed is confusing because a lot of information out there insist in not letting air package in the pots and tied as much as possible with the medium. As Roberta said the air circulaton among the roots in necessary, going from wet to dry with some ventilation in the best possible humid environment, that apply to big roots Orchids, there are other orchids with very fine thin roots that need to stay moist but no sucking wet, all the time.

That is true in general. It is like a bathroom after a nice hot bath - and then you keep the doors and windows closed so that the humidity stays in the bathroom .... and the nice warm and humid conditions are what mold/mildew/fungus tend to do well in ........ so not 'airing' the bathroom may result a fair bit of sooty patches on the walls ---- in between tiles etc. But adequate airing really cuts down (or even eliminates) that sort of thing.

It might mean that it comes from somewhere breezy (like Madagascar) and to compensate, give it extra Calcium during growth to help build healthier cells that will prevent fungus and bacterial infections. Some growers skip the Calcium but use a preventative or have a systemic fungicide on hand.

I know what you mean. Although - just considering plants (as we know them) doesn't have thinking functions ----- they don't have a 'want' as such. But to be able to stay alive, there will be a range of conditions that can allow the plant to stay alive for relatively long periods of time ----- to just keep going.

There can be conditions where a plant can survive with pretty much little to no air-flow - for months or maybe years. One example is inside a sterile flask with adequate nutrients in there, among other essential components.

The difference when the plant comes out of the flask - where other things from the environment can infuence the growth and/or health of the plant. So even outside of the flask ----- little to no air-flow can be encountered too ------ but doesn't always mean a bad outcome. The health of the plant will depend on what is in the environment, and how the plant is treated (and provided) - also including defending the plant against attackers.

Although - in general, it is beneficial to have some air-flow for general growing areas.