There's no 'correct'. Do what works for you. On small plants I sometimes snap off the whole of the top and it regrows side shoots. On larger plants I take side leaves. On plants that look as if they are preparing to bolt I snap out the centre which holds off flowering a little longer. When they do flower I use the blossoms in salad.

I just break off the bigger leaves from the plant and leave the smaller ones on the top. If they get too big, I just break them off and toss them and keep harvesting up the plant.

You can do this with any Kale. By the end of the season, some of the kale plants look like little palm trees!

Jay

To some degree, it may make a difference where you live. (Just one more reason why it's helpful for you to include your zone in every post.) In my zone, Kale grows all winter long, so I would not want to cut the entire plant. I harvest the larger lower leaves and leave the smaller top leaves to continue to grow. In this manner, I harvest continually from fall to spring from the same plants. Last year, I actually used Red Russian as the background of my pansy planting of Ultima Morpho pansies. It was a beautiful bed all winter and we ate from it too.

But, if you live farther north, it might be better to harvest the entire plant.

Red Russian Kale may just be my favorite green of all, and I like nearly all of them. It's delicious. Enjoy!

Even up north, we harvest the leaves and leave the growing tip. If the plant winters over, it will grow sweet side shoots in early spring (snap them off and eat them.)