Contrary to popular belief, most deciduous trees, those that drop all their leaves in autumn, are not as messy as most evergreen trees. There are of course a few exception; such as cacti that lack foliage completely, or Italian cypress that drop their finely textured foliage straight down within a very narrow drip-zone, where it decomposes and disappears unnoticed. Very few leaves fall from a big silver maple through winter, spring and summer, so that almost all of the raking is done when almost all the leaves get shed in autumn. However, a big Southern magnolia generally drops leaves throughout the year, so that raking is always necessary.
The problem is that when deciduous trees get to be messy, they are very messy. Also, they get to be messy at the worst time of year, when their leaves mix with rain to clog drains and gutters. Unraked leaves become hazardously slippery when they get wet and start to decompose. It is amazing how something that can be so appealingly colorful through autumn can so quickly become such a nuisance.
Leaves of deciduous trees somehow seem to be better for composting than those of some of the evergreen trees. Anyone with a Southern magnolia knows how slow the foliage is to decompose. Foliage of camphor, bay, carob and various eucalyptus certainly decompose slower than various maple, ash, poplar and birch. Many of us outfitted with green waste bins or curbside collection of green waste prefer to recycle the less desirable evergreen foliage, and compost primarily deciduous foliage. Those of us who do not compost but need to rake under large or many deciduous trees may fill bins for several weeks, or leave very big piles of leaves at the curb.
Small leaves, such as those of most elms, or finely textured compound leaves, such as those of silk tree, jacaranda or locust, may not need to be raked if they fall onto lower shrubbery or ground cover. Small leaves or the small leaflets of disintegrating compound leaves simply sift through the lower plant material to decompose below. However, large elms may produce such an abundance of foliage that some may need to be removed. Maple and other large leaves are not so easy to ignore. They can shade lawns, ground cover or bedding plants, so need to be raked as they fall.