Leave Flower Stems for Bees and Small, Solitary Wasps

Fall is a time when many people “put their gardens to bed” by cutting back their dead flowers and cleaning up their gardens before winter. However, if attracting pollinators to your garden is one of your goals, then you might want to rethink cutting old flower stems to the ground.

Stems with hollow or soft, pithy centers like this cup plant stem are Mother Nature’s original version of a bee hotel with removable tubes. Photo credit: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, CC BY 3.0

Some of our small, solitary, native bees and wasps build nesting cavities in old flower and plant stems. As you are doing your fall clean-up, leave 1 – 2 feet of stem standing, especially on plants where the stem is hollow or has a soft, pithy center.

Many of the small bees and wasps that use flower stems can’t chew through the tough outside layers of the stem. Instead, they rely on a break in the stem or a hole that was chewed in the stem by another insect. By cutting the stems back to 1 or 2 feet tall, you are exposing the hollow or pithy center and are providing nesting sites for stem-nesting bees and wasps to use when they emerge next year. Because next year’s wasps will be laying eggs in this year’s stems, you need to leave the stems for 2 years so that next year’s eggs have time to hatch, mature, and emerge as adults the following spring.

By leaving the stems in your garden, you are providing Mother Nature’s original version of a bee hotel with removable tubes. And next spring as your garden plants grow, they will hide the old stems while providing a safe, nesting location for our stem-nesting pollinators.

You can provide nesting habitat for our stem-nesting bees and wasps by not cutting old flower stems to the ground when you do your fall garden clean-up. Photo credit: Diane Wilson, CC BY-ND-NC 1.0

This article was part of Shannon’s original Kentucky Pollinators and Backyard Wildlife blog which evolved into the blog for Backyard Ecology.

Backyard Ecology: Exploring Nature in Your Backyard
Nature isn’t just “out there.” It’s all around us, including right outside our doors. Hi, my name is Shannon Trimboli, and I am the host of Backyard Ecology. I live in southcentral Kentucky and am a wildlife biologist, educator, author, beekeeper, and owner of a nursery specializing in plants for pollinators and wildlife conservation. I invite you to join me as we ignite our curiosity and natural wonder, explore our yards and communities, and improve our local pollinator and wildlife habitat. Learn more or subscribe to my email list at www.backyardecology.net.

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