(And Why Those Holes Are Actually Good)
Reading Time: 6 minutes
I'll never forget the panicked text I got from my neighbor three summers ago: "Something is DESTROYING my roses! Come look at this!"
I walked over expecting Japanese beetles or black spot fungus. Instead, I found the most perfect circular cutouts I'd ever seen - like someone had used a tiny cookie cutter on every third leaf.
"You don't have a pest problem," I told her. "You have leafcutter bees. And that's actually really good news."
She looked at me like I'd lost my mind.
But here's the thing: those perfect circles cut from your rose leaves, your lilac bush, or your redbud tree? They're not damage. They're architecture.
Let me introduce you to one of the most fascinating - and misunderstood - native bees in North America.
Those Perfect Circles Cut From Your Rose Leaves? Don't Panic.
First, let's address the elephant in the garden: yes, leafcutter bees cut pieces out of your plants. No, this is not a problem.
Here's why:
The "damage" is cosmetic only. Leafcutter bees take small pieces from the edges of leaves. They're not eating the plant, spreading disease, or causing any harm to the plant's health. It's essentially free pruning.
They're incredibly selective. Leafcutters prefer plants with thin, smooth leaves - roses, ash, lilac, birch, redbud. They avoid plants with tough, waxy, or fuzzy leaves. If they're cutting your plants, it means you're growing healthy, tender foliage. That's a compliment.
The cuts heal quickly. Within days, the edges of cut leaves begin to brown and seal. The plant continues photosynthesizing just fine. I've had roses that leafcutters visited every summer for five years - the plants are thriving.
You're witnessing something incredible. These bees are using your leaves to build elaborate, waterproof nurseries for their offspring. It's construction work. Art, even.
Once I explained all this to my neighbor, she went from horrified to fascinated. Now she watches for leafcutters every June and gets genuinely excited when she spots new cuts.
Meet the Leaf-Cutting Architects
Leafcutter bees (Megachile species - there are about 240 in North America) are medium-sized, robust bees that fly from early summer through fall. They're active when mason bees have already finished for the season.
Here's what they look like:
Most are about the size of a honeybee, but stockier and more compact. Dark gray or black bodies with distinct light-colored stripes across their abdomen. Many species have huge mandibles (jaws) - these are their cutting tools. Females carry pollen on their belly, which is often bright yellow, orange, or white when loaded with pollen.
The first time I properly identified a leafcutter bee, she was hovering around my roses at high speed, clearly evaluating which leaf to cut. She landed, walked along the edge, and then - in about 10 seconds - cut a perfect circle and flew off with it clutched in her legs.
It was like watching a tiny, flying craft project in action.
The Cutting Technique (It's Genius)
I've spent embarrassing amounts of time watching leafcutter bees work, and their technique is remarkable.
The Selection Process A female lands on a potential leaf and walks the edge, "tasting" it with her antennae and mandibles. She's checking for the right texture and thickness. Too thick, and it's too heavy to carry. Too thin, and it won't hold up structurally.
The Cut Once she's made her choice, she positions herself and starts cutting in an arc with her mandibles, rotating her body as she goes. It takes 10-30 seconds. The cut is so clean it looks machine-made.
The Flight Home She holds the cut piece under her body with her legs and flies back to her nest - often several hundred feet away. Watch a leafcutter bee in flight carrying a leaf piece and it looks like a tiny green flying carpet.
The Purpose Those leaf pieces aren't food - they're building materials. She's using them to line her nest cells, creating waterproof, protective chambers for her eggs.
I once watched a female make 18 trips in 45 minutes, each time returning with a perfectly cut leaf circle or oval. Eighteen trips. That's dedication.
The Underground Apartments Made of Leaves
Leafcutter bees are solitary - each female creates her own nest. But unlike mason bees (who use mud) or mining bees (who dig in soil), leafcutters are interior decorators. They find cavities and furnish them with leaves.
Here's the nesting process:
Finding Home Leafcutters nest in existing cavities - old beetle holes in wood, hollow plant stems, gaps in siding, or (if you're smart) bee hotels. They need a hole about 1/4" to 3/8" in diameter. For bee hotels www.crownbees.com offer the proper type and have lots of information about leafcutter bees too.
Building the First Cell Starting at the back of the cavity, the female lines the walls with oval-shaped leaf pieces, overlapping them like shingles. This creates a waterproof cylinder. The back end is sealed with circular leaf pieces - sometimes 8-10 layers thick. It's incredible architecture.
Provisioning She makes dozens of trips collecting pollen and nectar, creating a paste that fills about 1/3 of the cell. She lays an egg on top.
Sealing and Repeating She caps that cell with more circular leaf pieces, creating a partition wall. Then she builds another cell in front of it. And another. A single nest tunnel might contain 6-12 cells, each separated by leaf partitions.
The Final Seal The last cell gets sealed with extra leaf pieces, mud, or chewed plant material - creating a thick plug that protects the entire nest.
Inside those leaf-lined cells, eggs hatch into larvae. Larvae eat the stored pollen, grow, spin cocoons, and overwinter as prepupae. They'll emerge as adults next summer, ready to continue the cycle.
The whole thing is essentially an apartment building made entirely of stolen leaves. It's genius.
Why Leafcutters Are Pollination Powerhouses
People get so focused on the leaf-cutting behavior that they forget why these bees are so important: they're exceptional pollinators.
Belly-floppers Like Mason Bees Leafcutters carry pollen on their belly (the scopa). Every time they visit a flower, they're grinding pollen all over the stigma. This makes them incredibly efficient pollinators - much more so than honeybees.
Mid-Summer Specialists Leafcutters are active July through September in most areas - prime time for vegetable gardens, summer flowers, and crops like alfalfa. When mason bees are done and bumblebee colonies are winding down, leafcutters are just getting started.
Alfalfa Legends Leafcutter bees are THE primary pollinators of alfalfa, which is crucial for cattle feed. Some alfalfa farmers literally rent leafcutter bee cocoons to ensure good seed set. These small bees are responsible for millions of dollars in agricultural production.
Fast Workers Leafcutters are some of the fastest-flying bees I've observed. They zip from flower to flower with purpose, visiting hundreds of blossoms per day. They're not leisurely foragers - they're on a mission.
In my garden, I've noticed a direct correlation between leafcutter bee activity and the productivity of my late-summer vegetables. The more leaf cuts I see in July, the better my tomato and pepper pollination in August.
Identifying Leafcutters vs. Look-Alikes
Leafcutter bees can be tricky to identify at first because they're fast and don't linger. Here's what to watch for:
Size and Shape Stocky, robust body. About honeybee-sized but more compact and powerful-looking.
Color Most are dark gray or black with light bands on the abdomen. When carrying pollen, their belly is often bright yellow, orange, or white - very distinctive.
Flight Pattern Fast, direct, purposeful. Not the meandering flight of honeybees or the hovering of carpenter bees. Leafcutters move like they're late for an appointment.
Behavior Look for them on leaf edges, especially roses, lilac, and ash. Watch for the "evaluation walk" along the leaf margin before cutting. And of course, those perfect circular or oval cutouts are the telltale sign.
Sound Leafcutters have a distinctive high-pitched buzz - higher than a bumblebee, more insistent than a honeybee.
The best time to spot them is mid-morning through early afternoon on sunny days in July and August.
Supporting Leafcutter Bees (Yes, Even If They Cut Your Roses)
If you want to support leafcutter bees - and you should, they're incredible pollinators - here's what they need:
Let Them Cut I know it's hard to watch perfect foliage get cut, but please resist the urge to spray or cover plants. The "damage" is temporary and harmless. Consider it a badge of honor that your garden is healthy enough to support these amazing bees.
Provide Nesting Sites Leave some hollow stems standing over winter (raspberry canes, bee balm stalks, cup plant stems). Or put up a simple bee hotel with 1/4" to 3/8" diameter holes. Leafcutters will absolutely use them.
Plant Their Favorites For cutting material: roses (especially shrub roses), lilac, redbud, ash, birch. For nectar/pollen: coneflowers, black-eyed Susans, lavender, oregano, sunflowers, zinnias.
Skip the Mulch Leafcutters often nest in bare soil or use ground-level cavities. Heavy mulch can eliminate nesting opportunities. Leave some bare ground exposed.
Don't Use Pesticides This should go without saying, but leafcutters are especially vulnerable to insecticides. If you're spraying roses for other pests, you're likely killing the bees too.
I've had robust leafcutter populations in my garden for years, and yes, my roses and lilacs have circular holes every summer. But the roses bloom prolifically, and I get to watch one of nature's most fascinating behaviors up close. That trade-off is worth it every time.
Changing Your Perspective
Here's what I want you to take away from this:
Those circular holes in your leaves aren't damage - they're evidence. Evidence that you have healthy plants, a thriving ecosystem, and some of North America's most efficient pollinators working in your garden.
Next time you see those perfect circles, don't reach for the spray bottle. Grab a chair and watch. If you're patient, you'll see the bee return. You'll see her evaluate, position, cut, and fly off with her prize.
It's one of the most remarkable behaviors in the insect world, and it's happening right in your backyard.
Going Deeper
Want to learn how to identify leafcutter bees from other look-alikes, understand their complete lifecycle, and create the perfect habitat? That's exactly what I explore on The Secret Pollinators podcast.
I've got a whole episode dedicated to leafcutter bees - including the different species you might see, how to distinguish cutting patterns, and why their pollination services far outweigh any cosmetic "damage" to your plants.
Until next time - keep your eyes open. And maybe let your roses and lilacs keep a few imperfect leaves.
Kelly Parks Certified Pollinator Steward, Montana
Leafcutter Bee Resources
New to leafcutter bees? Start by looking for their signature circular cuts on roses, lilacs, and ash trees in mid-summer.
Want to provide nesting habitat? Simple bee hotels with 1/4" to 3/8" holes work perfectly. Leave hollow stems standing over winter for natural nesting sites. Check out www.crownbees.com for bee hotels and more information.
Have questions? Leave a comment or a voice message on my website - I read and respond to each one.
Thank you for reading!