Leave the Leaves

February 2020

Leaf litter is nature's gift to gardeners. Leaf litter is essential to many natural systems and cultivated spaces are no exception.

Decomposing leaves returns nutrients to the soil

California native plants need little in the way of soil amendments – they evolved to be adapted to California’s soil - but it doesn’t hurt to give them an extra boost of nutrients by letting dead leaves decompose. Various bacteria, fungi, and invertebrates (animals without a spine) munch through the leaves and produce nutrient-rich soil.

Leaf litter is free mulch!

Mulch and leaf litter have many marvelous benefits. The extra layer helps keep soil moist and cool during our summer dry season. The thick layer also aids in weed suppression making the task of hand weeding a little more manageable. It can also add gorgeous texture and beauty to your garden.

Sierran Tree Frog (Pseudacris sierra) using the leaf litter to hide.

Native pollinators and other animals need leaves

In addition to the salamanders, roly-polies, and other decomposers, many bees rely on leaf litter to keep themselves safe and warm during winter. Just as leaves provide insulation for soil to stay cool in the summer, they also help keep it warm in the winter. Bumble Bee queens, for example, hibernate in shallow holes just under the surface while the rest of the colony dies. These queens are responsible for re-establishing their seasonal colony when they emerge in the spring.

Western Redbud (Cercis occidentalis)

In Bloom

Western Redbuds (Cercis occidentalis) go beyond blooms when supporting our native pollinators. Its bright flowers attract hummingbirds, its flat leaves are a favorite of leaf-cutter bees, and it is deciduous which adds to your leaf litter. If you notice C-shaped cutouts on your redbud’s green leaves, you may have a female leaf-cutter bee who is harvesting material to build her brood cells. Consider installing a bee hotel to give leaf-cutter and other solitary bees a place to call home.

Redbuds are also an excellent for highlighting seasonal changes in your garden. In spring it erupts in a riot of small magenta blooms with the start of shiny heart shaped leaves. As summer turns to fall, leaves change to red and yellow before falling for the colder months. Early winter reveals long maroon seedpods that not only add interest on the shrub, but a unique texture to your leaf litter once they drop. With a little pruning, you can determine its size and shape – small tree to large, multi-stemmed shrub.

Find Out More

·       Xerces Society

·       The National Wildlife Federation

·       Welcome Bees Home (December 2019)

·       Attracting Native Pollinators, The Xerces Society

·       California Bee’s & Blooms, Gordon W. Frankie, Robbin W. Thorp, Rollin E. Coville, & Barbara Ertter