Leafcutter bees: what’s cutting circles out of your leaves?

You head out to check on your runner beans and something’s not right. Perfect little half-moons have been snipped out of the leaf edges, so neat it looks like someone went round with a hole punch. No slime, no droppings, no caterpillar in sight.

Before you start plotting revenge, we have good news. This is almost certainly the work of a leafcutter bee, and she’s one of the best friends your garden could have.

What does leafcutter bee damage look like?

It’s one of the easiest garden mysteries to solve, because the damage is so tidy. Look out for:

• smooth semi-circular or oval notches cut from the edges of leaves, never the middle
• clean edges, as if trimmed with scissors
• no insects, caterpillars, slime trails or droppings left behind
• a plant that’s otherwise healthy, with no discolouration, wilting or tunnelling

You’ll usually spot it in mid-summer on mature foliage. Seedlings are rarely touched.

Who’s doing it, and why?

Leafcutter bees are solitary bees. Unlike honeybees, they don’t live in hives. Each female builds her own nest in a hollow stem, a gap in old wood or a bee hotel.

Those neat leaf pieces aren’t food. She carries them back home, tucked underneath her, and uses them to line and seal little cells for her eggs. It’s cosy leafy wallpaper for the next generation of pollinators.

We think it’s one of the loveliest things happening in the garden all summer.

Which plants do they visit?

On the veg patch, French and runner beans are the favourites, with the occasional nibble on strawberries and other soft leaves.

In the wider garden, roses, wisteria and lilac are the classic targets, along with other thin-leaved shrubs.

Should you worry?

Not at all. A few notches in the leaf edges won’t harm your plants or your harvest. Your beans will keep climbing and cropping away quite happily.

Leafcutter bees are gentle, non-aggressive and brilliant pollinators. Every visit they make to your flowers helps your fruit and veg set. A few scalloped leaves is a very fair rent.

Please don’t reach for the spray

Never use insecticides on leafcutter bees. They’re beneficial, and killing them harms your whole garden, not just the plant you were trying to protect.

How to welcome them instead

We’d much rather you roll out the welcome mat:

• plant a pollinator-friendly patch packed with open, nectar-rich flowers
• put up a bee hotel in a sunny, sheltered spot
• leave some hollow stems standing over winter, so they’ve got somewhere to nest

Give them a home and they’ll pay you back in better fruit and veg all summer long.

So next time you spot those perfect little circles, take it as a compliment. Your garden has been given the seal of approval by one of nature’s hardest-working pollinators.