As autumn turned to winter, you may have noticed some of your neighbors chose not to remove the fallen leaves from their yards. You may also have seen “Leave the Leaves” yard signs or even the hashtag #leavetheleaves.
The basic idea behind “leave the leaves” is self-explanatory when it comes to fall garden cleanup, though there are some important points to consider. For me, the concept of “leave the leaves” in the spring is a little harder to understand. Do I have to “leave the leaves” indefinitely or can I rake them up at some point? And if so, how and when? How can I organize my garden in the spring, in a way that’s beautiful and harmonious, but does not undo all the important ecological benefits of having “left the leaves” in the first place?
This post will discuss some of the benefits of “leaving the leaves” in the fall (and not removing them too quickly in the spring) and give some practical tips for both spring and fall garden cleanup, following the “leave the leaves” principle.
Why to “Leave the Leaves”?
Though we have been conditioned to tidy up our gardens in preparation for winter, in fact, fallen leaves supply critical winter habitat for native pollinators and other invertebrates – butterflies, beetles, bees, moths, etc.
Native species that overwinter in the Anacostia Watershed include:
- Great Spangled Fritillary, which hatch in September/ October, and shelter in leaf litter until May, appearing alongside violets, their essential food source.
- Woolly Bear or Isabella Tiger Moth, with its unmistakable long, thick orange-brown bristles. They can overwinter in the woolly bear stage, freezing and going dormant, then thawing in the spring and feeding again. They may even do this for several winters before pupating. They are thought to have the longest life of any moth or butterfly, living upwards of 10 years.
- Red-Banded Hairstreak, which lay their eggs on the undersides of fallen leaves of oak, sumac and wax myrtle. Larvae are reported to feed on dead leaves and detritus in the leaf litter.
- Luna Moth, also known as the American moon moth, which only lives for about a week after leaving the cocoon in the spring and is a favorite snack for bats!
- Swallowtail butterflies, which love to snack on parsley and dill, spending the winter as a chrysalis and emerging in the spring as gorgeous butterfly.
In addition to supplying habitat for native species, fallen leaves are a cost-effective (free!) mulch that will help control weeds and absorb moisture thereby hydrating your garden, minimizing soil erosion, and supplying essential nutrients for plants.
What to do when spring rolls around?
Once you’ve created a hospitable winter environment for pollinators and other invertebrates, you may be wondering what to do when spring comes. Many gardeners can’t wait to get out and begin “spring cleaning” as soon as the first warm day arrives.
Please resist the urge!
Many insects are still dormant in early spring, and may have taken up winter residence in the hollow stems of plants. A too-early garden cleanup can disturb their habitat and harm their chances of survival.
Ideally, you should wait to do your “spring cleaning” until the temperature is reliably about 50 degrees for at least 7 consecutive days. In the DMV, that likely means the month of May. When you tidy up, consider these tips (fromhttps://savvygardening.com/spring-garden-clean-done-right):
- Cut, bundle, and tie plant stems
- You can cut perennial and woody plant stems, leaving about 8 inches behind (which will serve as future habitat for insects), and then toss them very loosely on the compost pile or at the edge of the garden / woods – enabling many to survive and emerge as the weather warms.
- Or, take the cut stems, gather into bundles of a few dozen stems each, ties with twine and hang on a fence or lean at an angle against a tree. Leave the cut stems as future habitat for insects including native bees.
- Clean up leaves carefully
- Wait to clean up leaves until daytime temperatures consistently reach the 50s, if possible, and when you do, keep a careful eye out for butterflies, beetles and other beneficial insects and do your best not to disturb them.Wait to mulch
- You should also wait for the temperatures to reach the 50s consistently before doing your spring mulching, to give insects that overwintered as eggs, pupae or adults a chance to emerge from the soil.
Prune cautiously
- Finally, be very careful when pruning back woody perennials or shrubs to avoid removing branches with cocoons and chrysalises.
How to “Leave the Leaves” in the fall?
Even if you decide to “leave the leaves” in your garden at the end of autumn, you still have some tasks to be done and decisions to be made.
First, the vegetable garden is one spot in your yard that calls for a thorough cleanup – as spent crops and residues could carry over diseases and pests from one season the next. After you remove those, consider sowing a cover crop or mulching to protect the soil from winter weather.
Remove fallen leaves from ponds, where they could otherwise rot and impact water quality over the winter.
You can rake leaves from garden paths and paving for safety’s sake. If you have a lawn you may want to mow over autumn leaves, allowing the lawn to breathe and enabling the leaves’ organic matter to return to the soil. Also, some early blooming bulbs may not be able to push through a heavy layer of leaves in the spring, and fallen debris around the perimeter of peonies, roses and fruit trees might harbor disease, so you may want to rake those spots in the fall.
Any leaves you need to relocate in the fall can be raked to your garden’s edge or to your vegetable beds. Creating leaf (and log) piles that remain in the garden over the winter and break down naturally is a great idea. If you have concerns about ticks residing in your leaf litter, move it to the area of the yard furthest from your house.
Conclusion
Many of the ideas and tips in this post run counter to what we have learned throughout our life as gardeners – including the thorough “fall cleanup” and “spring cleanup” which have to some degree become ingrained parts of our gardening culture. Unlearning these habits can be hard, but choosing an eco-conscious spring and fall cleanup enables you to contribute to the health of the local ecosystem, while still enjoying all the incredible benefits of gardening: exercise, stress relief, natural beauty and Vitamin D!
For additional resources on environmentally friendly fall and spring garden cleanup, see:
https://xerces.org/blog/dont-spring-into-garden-cleanup-too-soon
https://xerces.org/blog/leave-the-leaves
https://www.washingtonpost.com/home/2023/03/08/garden-spring-cleaning-insect-habitat/
https://www.nytimes.com/2020/09/30/realestate/fall-garden-cleanup.html