Daf Yomi - Sukkah 13 - Pathetic Chrein

One cannot use for s’chach the vegetables that can be used for maror on Pesach, as these vegetables are generally very delicate. The reason for this ruling is because these vegetables are very delicate and in all likelihood they will dry up and disintegrate, so they are deemed to be non-existent from the outset. The Mishna in Pesachim lists tamcha as one of the vegetables that one can use to fulfill his obligation of eating maror on Pesach. Tamcha is commonly defined as chrain. The Pischa Zuta wonders how it can be said that chrain will dry up and disintegrate, as chrain is not known to be delicate.

I have not yet found an answer to this question.