Creating Habitat for Stem-nesting Bees
Did you know? About 30% of Maryland’s native bees nest in tubes and tunnels. Very few of these species are able to excavate their own nests too. In a previous Habichat, we covered how to make nest blocks for bees. This article will cover how to create habitat for those that nest in stems of flowers and woody plants.
To help stem nesting bees, you should include pithy flower stalks and soft, pithy wood in your backyard as nesting locations. Pithy plants have spongy, soft tissue in the central stalk of the plant. Plants with hollow piths are also ideal for nesting.
Plants that provide this habitat include:
- Hyssop (Agastache foeniculum )- non-native
- Swamp milkweed (Asclepias incarnata) – native
- Joe pyeweed (Eutrochium purpureum) – native
- Purple coneflower (Echinacea purpurea )- non-native
- Blazing star (Liatris sp.) – native
- Wild bergamot (Monarda fistulosa) – native
- Mountain mint (Pycnanthemum sp.) – native
- Goldenrod (Solidago sp.) – native
- Culver’s root (Veronicastrum virginicum) – native
Simply adding these plants is the first step in this process. The next step is to allow the flower stalks to persist through the following spring. Here is a recommended timeline from Satyshur et al. (linked under references):
- Plant native plants and cut back dead flower stalks varying heights of 8 – 24 inches. These stalks will provide nesting habitat for female bees.
- Female bees will create a pollen ball, lay an egg, and then create a chamber in the stalk. She will repeat this process to the end of the stalk and will seal off the nest.
- New growth will surround the cut-back stalks and will provide nectar and pollen for other pollinators.
- The bee larvae will continue to develop on the stem.
Fall and Winter:
- Leave dead flower stalks standing over the winter. Bees will hibernate in the stems during this time.
- Cut back dead flower stalks. They will decompose and adult bees will emerge. The process starts all over again with new growth!
Additional habitat for cavity-nesting bees includes rotting logs and standing dead trees (snags). Consider leaving both in your backyard as bee nesting habitat if it is safe to do so. Adding pithy woody plants, such as elderberry (Sambucus canadensis), sumac (Rhus spp.), and raspberry (Rubus spp.,) will also provide habitat for stem-nesting bees. To see a graphic of cavity-nesting bees that use flower stalks, check out this PDF from Heather Holm.
Holm, H. 2017. Bees: An Identification and Native Plant Forage Guide. Pollination Press LLC.
Satyshur, C. and E. Evans with contributions from Sarah Foltz Jordan, Xerces Society and Heather Holm. Photos by Heather Holm, Colleen Satyshur and Thea Evans. 2020. How to create habitat for stem-nesting bees. https://www.beelab.umn.edu/sites/beelab.umn.edu/files/stem-nesting-bee-handout-v5.pdf Accessed September 2, 2020.
Spending more time at home means I’m spending more time in the backyard. I have been in awe at the sights I have missed over the years. Lately, I have been watching the backyard monarchs as if they were my own children! As the days get shorter, here are a few things to consider this time of year:
I’m also excited to announce the new Wild Acres public events page which will feature upcoming webinars sponsored by the Wildlife and Heritage Service. In addition, the Gardening for Pollinators webinar is now available on-demand. HabiChat subscribers will receive webinar updates as they are scheduled.
Furthermore, if you are in need of trees and shrubs for conservation or lumber, check out the Maryland State Tree Nursery which will soon be accepting orders for Spring 2021.
In this issue, you can learn about the lovely black and yellow garden spiders which can be seen this time of year, as well as information on the vigorous, native switchgrass. Additional articles include information on the importance of warm season grasses and why leaving flower stems up through the winter helps pollinators.
In this Issue