Finland, it would be helpful if we knew what plants you are speaking of.

Hi rhizo, one is Mizuna Greens and the other is Tatsoi Bok Choy.

I would guess that only the leaf itself is meant.

Alright, thank you for the help.

In these examples, the soft leaf stalks (petioles) are considered part of the edible leaf. See what I mean by this image of Tatsoi , something that I'm going to plant for next year.

I grow Mizuna now, snipping the entire leaf and petiole to harvest. As always, the younger the leaf, the more tender it will be.

If you allow greens to mature, they will probably need to be trimmed of tougher portions. My personal preference is to harvest greens for eating fresh, though I love a pot of cooked greens, too.