I think the team here at GrowVeg has done a great job providing solid information on ways to use leaves in your garden. Ben’s blog on Making Leaf Mold - Gardener's Gold (2011) opened a lively dialog on leaves, to which I added my experiences in Using Leaves in the Vegetable Garden (2013). Our tips (plus many more) made it into the 7 Ways to Use Leaves in Your Garden video, which may be the best five minutes you will ever spend as you contemplate what to do with this year’s crop of leaves.
Having these blocks of information in place gives a garden writer a false sense of security, as we assume that everyone has read everything and therefore knows all they need to know. Then you get out in the world, and see evidence to the contrary: mountains of discarded leaves mixed with plastic that have become the responsibility of municipal composting facilities.
The yard waste composting facility I visited in Manassas, Virginia, was doing a stellar job of turning unwanted leaves into compost, but the thing that haunted me was how many people regarded bags and bags of leaves as trash. Clearly, educational efforts should continue.
Using Leaf Mold on Your Soil
We do our best to stay on top of reader questions, but over the years several worthy ones have slipped by, such as whether or not leaves will make the soil too acidic. This could happen if you shredded large amounts of newly fallen leaves and mixed the tiny pieces directly into soil. However, if you use whole or chopped leaves as mulch, or allow your leaves to weather outdoors through winter, or let the leaves rot completely before using them, your soil pH is not likely to change.
Another common question concerns timing, or when leaves are ready to be used as mulch, or turned under and mixed with garden soil. The choice is yours, but I love using weathered leaves to mulch my potatoes, and the natural order of things involves turning under the leaves (or what is left of them) after the potatoes are harvested. Another way is to simply wait until most of the leaves have rotted, leaving behind mostly leaf veins, which take a little longer.
Leaf Mulch and Slugs
There is no doubt that leaf piles and leaf mulches provide good habitat for slugs, the most common garden pest many climates. Consider this comment: "I'm concerned about mulching with leaves here in rainy Seattle, where wet leaves are slug havens (we have to clear leaves from anywhere near our garden, as the slugs hide out underneath them). Is there a way to mulch with leaves in a rainy climate, without encouraging snails and slugs?"
No, but then there is no such thing as a slug-deterring mulch. In slug-prone environments, it is better to forego mulching, and either compost your leaves or manage them in a separate pile to produce leaf mold. Then, use the compost or leaf mold as soil amendments. Should there be slug eggs present in the compost or leaf mold, allowing it to dry in the sun for a few days will kill most of them. This is also a great job for chickens, who happily remove slugs and other creatures from leaf piles.
Speaking of chickens, last year I used bags of dry leaves as my main winter bedding material in the chicken coop, and we all loved it. The chickens enjoyed scratching through the leaves, just as they do outdoors, and their fancy footwork transformed crunchy dry leaves into a shredded, de-slugged version ready for the compost pile. I saved the plastic bags I used to collect the leaves, and plan to reuse them for several years.