One problem with that is bugs. Leaves and other mulch make great hiding and breeding area's for all kinds of unwanted bugs.There was a book about 40 years ago about gardening without tilling using mulch. The author piled leaves in her garden and planted by pulling the mulch back, planting starts, and pushing the mulch back to the plant. She added mulch whenever she had any. Claimed it kept the weeds out and fertilizer at the same time. I can't remember the name of the book or author. May have been published by Rodale Press.