I recommend putting them down in the fall before winter. I go as far as shredding them and placing them around my bulb gardens, asparagus, strawberries. I also til them into my vegetable garden beds. Maple leaves are a very good mulch. You may want to shred and pile them up into a compost area and they become deep dark rich soil in the spring.

My hubby shreds them with the mower and piles them on the flower beds. I leave them there in the spring and the decompose into the soil. By mid summer they are all gone.

Danni