Organic gardening is about two things: weed control and pest control. Successful gardening is about supplying the plants with nutrients and sufficient moisture.
One of the important elements of Permaculture is to mimic the systems found in nature. As leaves fall from the trees to the ground in a forest, they form a natural mulch that builds topsoil. We can follow this example by using leaves as mulch in our garden.
In the garden, if bare ground is exposed to sun, weeds will grow. Weeds compete with your plants for food and moisture. Weeds provide safe haven for insects. Covering the spaces between your plants and between your rows with mulch prevents weeds from growing, saving you hours and hours of manual labor, weeding by hand or with a hoe. Mulch also protects the soil from the sun, trapping and preserving moisture.
Many people mulch with straw and we will use wheat straw in our garden for certain plants or when we have used up our preferred leaf mulch. However, all wheat or rye straw will still have some bits of grain. Eventually these will sprout and produce some of the most difficult to remove "weeds" you are likely to encounter.
We do our best to avoid this by leaving the straw exposed to the weather for one year before using, so that any remaining grain will rot. While this will remove the viability of most seeds, some will survive and eventually sprout, becoming a plant that must be removed. Straw is also expensive and the price goes up every year. Straw sold to farmers for barn bedding is increasingly produced as large round bales rather than the tradition small, square bales. The round bales are extremely heavy and difficult to transport. All the more reason to consider leaves as the better alternative.
Where I live in Tennessee, my home is surrounded by towering oaks, hickory, and other types of trees. To preserve the lawns around our homes and the public buildings in my community, the leaves must be removed. It’s a win-win situation.
I use a mulching lawn mower with a bagger and dump the chopped leaves into plastic garbage bags. I collected over 50 bags last fall. It is important to use heavy duty bags or cover and protect them in some way so that the bags are not exposed to the elements and break down before you are ready to use the leaves the following summer. If you live in or near a city, you can often find leaves already bagged, along sidewalks, ready for the local landfill. Just drive through a suburban neighborhood in the fall and you are quite likely to fill a pickup with bagged leaves in no time!
You can also use raked, un-chopped leaves, which will produce a tighter, flatter layer of mulch above the soil. I will place these around water spigots and on paths, areas that get a lot of traffic.
Tree roots reach deep down into the ground pulling up trace minerals to feed the leaves. As your leaf mulch breaks down, it can be tilled directly into the soil, introducing organic matter. Leaves: free, abundant, and good for the soil! The perfect mulch!