Drowning a plant - how long is too long in water?

[JeffreyR]

I know that overwatering a plant can lead to rot and all kinds of problems. I’m not asking about that.

I want to know if it is possible to drown a plant by leaving the root, or the whole plant, submerged for too long?

As I read up about orchids, and some other plants, I often see instructions to “Soak the roots for 24 hours in…” or “Soak the whole plant overnight and then…”

I’m growing mainly Phals, indoors, at the present time, and they are doing well... Consistently growing new leaves, spikes, roots, flowers. Very little in the way of pests or disease.

Thanks in advance for helping a beginner.