I have a lot of both oak and maple leaves, and I mulch them all with my tractor, and I have a big lawn. Since you use small electric mower, I assume you have a small lawn but big trees?

Make sure your blade is sharp, and the leaves are as dry as is practical. Then run over the same swath of grass at least three times, and see what's left. The leaves don't need to be chopped fine like confetti. If you break them into pieces less than 2 inches long, you should be fine. They bigger pieces will lay on top of the grass for a while, but here at least, they eventually fall between the grass blades and disappear. Besides a sharp blade, the other key thing is not to let the leaves build up too much in the first place. I go after my leaves at least once a week in the Fall, and sometimes twice a week.

Sometimes, depending on how many leaves there are, I do need to mow an area two, three, or four times. Contrary to what some people have told me there is no law, natural or man made, that prohibits you from mowing any area more than once on any given day. Lawn mowing is not a competative sport.

Well I experimented and learned that I can't do it. I mowed a strip two or three yards wide and went over and over it about eight times. Other kinds of leaves would be chewed up fairly small in a few passes but mine are nearly all oak leaves. These huge sturdy leaves seemed to avoid being cut at all or maybe got down to 1/4 size after many passes. And of course that is also why they smother stuff if not removed. Darn. I had better get raking the deep leaves on my lawn or hire someone with heavy equipment.

Joyce--before trying anything else, you might consider trying a sharp, non-mulching blade in your mower. Mulching blades are designed for mulching grass, and not necessarily leaves. Your mower might be holding the leaves too high in the deck well, and passing over two many other leaves. A non-mulching blade wouldn't do that.

Also, are you sure the blade is sharp?

And does your mower have a mulch cover? If so, you might try cutting up the leaves with the mulch cover off.

You could get a handheld blower/vac. When on the vac option, they chop the leaves like a chipper. You could get one of these, take the bag off, and walk all around your yard sucking up whole leaves and letting the shredded one come out the back onto your lawn again. Maybe take the previous advice and have the mower blades sharpened, too.

Apply extra organic fertilizer may after all the leaves have fallen would help speed up decomposition of the leaves. Oak leaves seem to take a while to break down.