Its true of all grass eating species. CDTs, SA leopards, galaps, Burmese stars...May be true with sulcatas but not my leopards. They seem to stick with the shorter stuff and in summer they only get food from me about once a month. The longer stuff goes mostly untouched. More the grand then some of the weeds.
The reason your leopards don't eat the long stuff is because they get enough food from other sources, and also because regular leopards aren't that keen on grass anyway. I don't think it would work as well with a Russian or a hermanni.

