I use leaves that we pick up with our lawn tractor with the grass/leaf pickup attachment. The leaves are shredded from the mower they never mat or cause any problems in the garden. We have been using this method for mulching for many years, the leaves are from our neighborhood containing mostly maple although there are a variety from other trees with few if any oak leaves.
I have never had a plant get smothered to death with a leaf mulch, love it for helping keep weeds out, holding in moisture, and adding fertility to my garden we have lots of earth worms in the garden.
Added: Some of the leaves are brought over by neighbors that have not been run thru a mower they are put on as they are and cause no problems.
