I have an adult sulcata that has for the last 8 years had access to fallen leaves from 2 large maple trees. A few years ago I started keeping him outside all year. I would rake the fallen leaves into a pile around the base of one of the trees to use as mulch or substrate for some smaller tortoises, I noticed him eating the dried leaves that had blown from the pile or were missed when raking, but not the packed wet ones in the pile around the tree. The past couple years I haven't done any raking and he grazes on leaves all winter. I don't know if they benefit him, but they don't seem to hurt him. He is 18 years old, Had him since a hatchling, weighed him last week for the first time in years, he is now 128 pounds. Here he is this afternoon with his buddy Rocket in the background.