Moonhowl said:True, but you can use both...just top dress with the shredded leaves. Stretches the life of your mulch and still looks nice.
I think this is the way to go. In my experience, the shredded leaves don't hold moisture as well and therefore don't provide worms with the best conditions to thrive. I don't know if I'm drawing a solid conclusion there or not, but I do know that keeping my leaves and mulching with them has transformed my soil in a little less than four years. Initially I would find one worm in maybe every third shovel of dirt. Now I find several each time I turn the dirt over.
Check out this big dude I found last weekend. I get excited every time I find a worm this size. For reference my ugly shoe there is a size 13.