It is recommended to tie together leaves of some vegetables. I tried that with Chin. L. as well as with End. But the C.L. started to rot in the heart, perhaps because of the water trapped inside. The End. became a victim of slugs, wilting and rot under the bucket I put over them. (Covering prevents a regular check for e.g. slugs.) How to go about with tieing up?
In the case of endive, the reason for blanching is to reduce the bitter taste of the leaves. If covered too long, they rot. Two to three weeks is enough, the longer time in cold weather. Slugs can be a problem.