To rake or not to rake -- that is a burning question among gardeners. On one side are those who prefer pristine lawns and semi-formal beds, opposed by the other side’s preference for a more natural look that invites wildlife to find a home in the garden. Both sides make valid points, and there are neither strong advantages nor disadvantages to raking, according to Barbara Murphy, of the University of Maine Cooperative Extension, making it largely a matter of personal preference.
When left on your planting beds, leaves provide a winter mulch that helps maintain soil moisture and temperature levels, as well as protecting tender plant roots and stems from frost damage. Since most grasses enter a dormant period during the winter, they don’t need sunlight as much for food manufacturing, so the leaves won't smother the lawn, as many believe, as long as they aren’t too heavy. Maintain a 1/2-inch or thinner layer on the grass, although you can add thicker piles in planting beds and under trees, where they will also help with weed control.
Food for Thought
As the leaves decompose, they replace vital nutrients in the soil. In fact, composted elm, maple and oak leaves return twice as much calcium, phosphorus and magnesium as manure, according to Scott Hininger of the University of Wyoming Extension. To facilitate composting and prevent thick mats of leaves on your lawn and garden, set your rotary mower at a 3-inch level and mow over the leaves several times, reducing them to 1/2-inch pieces.
When you put your raked and bagged leaves out for pickup, it costs you and the rest of the taxpayers for collecting, transportation and disposal. Then, when you go to the garden center for organic fertilizer, you pay as much as $15 for the same composted leaves from a single tree, according to Hininger, so shredding the leaves with the mower and leaving them in the yard saves you money. Also, when you remove the leaves around trees and from planting beds, the soil is more vulnerable to erosion. Finally, when you leave the tree’s dropped foliage where it falls, you keep the raked piles from washing into drainage culverts and waterways, where they foster algae growth, which can lead to fish kills from oxygen depletion in the water.
It may sound like you’re off the hook for raking leaves this year, but there are still some rather compelling points to consider. First, leaves on sidewalks, patios and decks may cause slips and falls, especially when they get wet. Compromise by clearing those areas and adding the extra leaves to your planting beds. Another concern is that your homeowners’ association or neighbors may not share your love of a natural habitat, but you can keep everyone happy by clearing the areas that are most obvious from the street, again composting the leaves you remove from high-traffic areas. Thick layers of leaves can cause lawn damage or deprive the newly awakened spring growth of needed sunlight. Shredding the leaves with the mower will help considerably, but using that rake may be necessary to some of them to keep the thickness to the optimal 1/2-inch level. Finally, both beneficial insects and pest may overwinter in the leaves, including slugs and snails, which love the chopped compost for egg laying. You can provide a nice home for helpful bugs while controlling the rest by raking in areas where you’ve had pest infestations in the past and leaving them alone in the rest of the garden.