Leave the Leaves: Fall Garden Cleanup That Helps Pollinators

Fall cleanup has a long tradition: rake every leaf, cut every stem to the ground, bag it all up. It looks tidy. But for a lot of the insects we want in our gardens, that tidy yard is an empty one. Many native bees, butterflies, and other helpful insects spend the winter right in the leaves and stems we're throwing away.

The good news? Helping them means doing less work, not more.

Who's Living in Your Leaves

• Bumble bee queens. After summer, only the newly mated queens survive. Each one tucks herself into loose soil or under leaf litter for the winter, and in spring she starts a brand-new colony alone.
• Ground-nesting bees. Most native bee species nest in the ground, and a layer of leaves insulates them from cold and wet.
• Butterflies and moths. Many spend the winter as eggs, caterpillars, or chrysalises tucked into fallen leaves.
• Beetles, spiders, and other garden helpers that eat pests and feed the birds.

Honey bees are different; they spend the winter clustered together in the hive. (Here's how we get our hives ready.) But the wild pollinators in your neighborhood depend on habitat like this.

What to Leave

• Leaves in your garden beds. Rake leaves off the lawn (a thick layer can smother grass) and spread them under shrubs and over flower beds instead. They break down into free mulch and feed your soil.
• Hollow and pithy stems. Plants like salvia, bee balm, coneflower, sunflower, and elderberry have stems that small bees use for nesting. Leave them standing over winter.
• Seed heads. Birds love them, and they add winter texture to the garden.
• A patch of bare soil. Ground-nesting bees need some unmulched, sunny ground to dig into.
• A small brush or log pile tucked into a back corner.

What to Clean Up

"Leave the leaves" doesn't mean leave everything:

• Diseased plants. Remove anything with rust, mildew, or blight so the problem doesn't carry over. Tomato and squash debris is a common one. Bag it instead of composting it.
• Weeds going to seed, before they drop next year's weeds.
• Paths, patios, and walkways, where wet leaves get slippery.
• Anything near your house. In fire-prone parts of California, keep dry leaves and plant debris cleared from roofs, gutters, and the area right around your home. Save the leaf layer for beds farther out.

When to Cut Back in Spring

Wait. Insects overwintering in your garden need warm weather to wake up and move on. A good rule of thumb is to hold off until daytime temperatures are consistently in the 50s and fruit trees are blooming. In the Bay Area, that's often March.

When you do cut back, try this: trim dead stems to different heights, between about 8 and 24 inches, and leave the stubble standing. New growth quickly hides it, and the hollow stubs become nesting sites for next year's stem-nesting bees. Leave cut stems in a loose pile for a few weeks before composting, so anything still sleeping inside has a chance to emerge.

Making Peace With a Wilder Look

If a less-than-tidy yard makes you twitchy, start small. Leave the leaves in one bed, or let one corner go wild. A neat edge along a path or lawn makes the rest look intentional. A little sign helps, too: neighbors are a lot more understanding when they know it's on purpose.

Let your neighbors know what you're up to with our Welcome to Our Pollinator Garden flag, and see What to Plant in October for Happy Bees Next Spring.