Pausing on pruning can benefit countless beneficial species in the garden.
Courtesy Erica Browne Grivas
As the ground warms, and organisms from microbes to mammals rev up for spring, there’s a lot of confusion about how to be gentle to the Earth while gardening.
On social media, memes are flying asking us not to clean up spent winter foliage or to skip mowing the lawn in May entirely (a movement dubbed “No-Mow May”).
Yet risking even a brief glance at the comments section reveals widespread confusion and division.
Perhaps you’ve been repeating this annual clean-up ritual in fall and/or spring, and it sounds like inviting inevitable chaos to stop it. Perhaps you’re on board with the concept but are confused about how and when to prune, if at all. Let’s start with why you might want to stay or alter your spring clean-up in the garden.
Why skip clean-up?
First, the exception: removing the three D’s — dead, damaged or diseased — biomass is always recommended. It’s healthier for the plant and its companions.
While leaf litter, spent stalks and seedheads look like a mess to an eye used to manicured perfection, they provide critical shelter and nourishment to overwintering beneficial insects and pollinators, including bees, butterflies, and birds.
In the face of habitat loss due to urbanization, these creatures are declining in massive numbers – yet even a window box or a small patch of earth has the power to save a hungry bee or migrating bird during the lean times of winter.
A blanket of fall leaves on the ground keeps the ground and all its nesting creatures warm. Removing or shredding the leaves interrupts or ends that cycle. A recent study (https://www.sciencedirect.com/science/article/pii/S0048969725004565) showed that leaf removal decreased the spring emergence of butterflies by 45%, and reduced the diversity of butterfly populations by 40%. The more diverse creatures our gardens support, the healthier our ecosystem will be.
Many beneficial insects overwinter in the cozy shelter of hollow stems, and butterfly and moth chrysalides attach themselves to stems and fallen leaves.
When, if, and options on how to “clean up”
One guideline, according to the Xerces Society (https://xerces.org/blog/dont-spring-into-garden-cleanup-too-soon), is to wait until temperatures are reliably over 50 degrees Fahrenheit – including at night – to allow overwintering insects to emerge from their winter resting spots. Species all have personal preferences, so there’s no hard and fast date for everyone; that’s why you’ll see some brave bees on your hellebores on a sunny January day. If this number sounds familiar, that’s also the minimum temperature tomato plants will begin growing. So, have you planted your tomatoes in the open air yet? If no, step back inside with the pruners.
While temperatures vary widely across regions, another cue is bloom times. Waiting until the apple and pear trees are finished blooming should be a safe time for most overwintering beneficial creatures.
If you can be patient, skip pruning altogether.
Designer and Midwest-based wildlife advocate Benjamin Vogt, author of “Prairie Up,” and “A New Garden Ethic,” tries his best not to prune. He questions the need to clean up at all – why not design for wildlife and make it look beautiful? If he does prune, he leaves stems 18” high, knowing that spring growth will soon cover those bare stems.
If for some reason, you need to clean up early, try this extra life-saving compromise: chop and drop.
Cut or pull out the stem but lay it on the ground. If you can leave it there, it will compost and nourish the soil. If you must remove it, do so after several warm days to allow the insects time to move out.
The elephant in the garden: lawns and “no-mow May”
“No-mow May” was conceived as a kind of training wheels intro to wildlife gardening. The idea is let your lawn go “wild” in May and allow insects to emerge and any flowering plants in the lawn to bloom. In addition to supporting pollinators, it requires less work.
However, there are reasons to rethink this plan. According to Scotts Miracle-Gro experts, going a month without mowing weakens your lawn, encouraging weeds and pests, which encourages gardeners to non-wildlife friendly interventions.
Matthew Koch, Ph.D., Director of Biotechnology and Genetics at The Scotts Miracle-Gro Company, says, “For most lawns, going an entire month without mowing can actually do more harm than good. Overgrown grass blocks sunlight, limiting the plant's ability to make energy and weakening the turf….Plus, the steps needed to address these problems would likely counteract the benefits that an overrun lawn would provide to pollinators.”
Instead, Koch recommends incorporating biodiversity year-round by adding pollinator-friendly groundcovers, planting clover lawns, or designating specific areas for naturalization.
A broader view is worth considering. While temporary measures like “No-Mow May” raise important awareness, replacing all or part of a traditional lawn with more ecologically valuable plantings has greater, lasting benefits.
Lawns, especially when conventionally maintained with high water use and chemical inputs, offer negligible environmental benefits and can cause significant harm to waterways and ecosystems.
Where a lawn-like appearance is needed, consider resilient alternatives like mini clover or native meadows (which can go months without mowing). Adding bulbs such as snowdrops or crocus into an existing lawn can also provide critical early food for pollinators while maintaining a familiar green space.
Looking ahead
There’s a paradigm shift underway in how we view wildness and a little 'chaos' in the garden — and it couldn’t come at a more critical time. By welcoming a wilder, richer garden, we’re offering a lifeline to the insects, birds, and other creatures whose survival is intimately tied to our own. And in return, we’re rewarded with a beautiful garden that’s healthier, more resilient, and full of life.