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7 Native Plants to Grow for Stem-Nesting Bees (and How to Maintain Them!)

Lauren Landers
3 days ago
5 min read

Monarda fistulosa Photo Credit: Martha B. Moss — *Monarda fistulosa* Photo Credit: Martha B. Moss

While European honeybees live in hives, most of Maine’s native bees are solitary insects that hibernate and lay eggs underground, in old leaf litter, or in the hollow stems of native plants. Growing plants with hollow or pithy stems which can be easily excavated by stem-nesting bees is one of the easiest ways to make your garden more pollinator-friendly and help bees and other pollinators make a comeback. Here are just a few Maine native plants that you can grow for stem-nesting bees, plus maintenance tips to ensure your plants provide the most benefits for native pollinators!

Joe Pye Weed (Eutrochium spp.)

Maine has several species of native Joe Pye weed, including spotted Joe Pye weed (Eutrochium maculatum) and hollow Joe Pye weed (Eutrochium fistulosum). These plants both grow between 5 and 10 feet tall and produce airy clusters of fragrant, pinkish-purple blooms in summer. Joe Pye weed flowers are highly attractive to pollinators of all sorts, while their hollow stems provide ideal winter shelter for native bees. These plants also tolerate wetter conditions than most ornamentals and are well-suited for rain gardens.

Elderberry (Sambucus canadensis)

Elderberry is mostly known as a medicinal plant and it’s also a great plant to grow for attracting fruit-eating birds, like cedar waxwings. However, elderberry can also be grown as a sheltering plant for stem-nesting bees who dig out the soft interior of the plant’s pithy stems and nest inside. On top of that, elderberry flowers are also highly attractive to pollinators, and they perfume gardens with a citrusy scent in summer!

Swamp Milkweed (Asclepias incarnata)

Another fine choice for rain gardens and beds with soggy soil, swamp milkweed is more water tolerant than common milkweed, but it’s just as attractive to pollinators. This plant grows between 2 and 5 feet tall and typically produces its pinkish-purple blooms from July to August. After flowering, swamp milkweed stems provide shelter for pollinators all winter long, and the plant readily self-sows if you don’t remove the spent flowers.

Purple Flowering Raspberry (Rubus odoratus)

Unlike your average raspberry plant, purple flowering raspberry is thorn-free and fragrant and produces large, pinkish-purple flowers that look a bit like Rose of Sharon blooms. These plants are commonly found along forest margins, but they add charm to gardens when they’re planted beside fences or grown as specimen plants on their own. Beyond their hollow stems, flowering raspberry feeds pollinators of all sorts with its nectar-filled flowers, and yields berries, which are edible but not as tasty as standard raspberries.

Bee Balm (Monarda fistulosa)

Also known as wild bergamot, bee balm belongs to the mint family, but it doesn’t grow as aggressively as some mints. Traditionally, this plant was often grown as an edible and its oregano-like leaves were brewed into a flavorful, herbal tea. However, bee balm has plenty of ornamental appeal as well, and it provides food and shelter for a wide range of pollinators, including native yellow-faced bees (Hylaeus spp.)

Mountain Mint (Pycnanthemum muticum)

Like bee balm, mountain mint is a member of the mint family, but it doesn’t grow as aggressively as plants like spearmint and peppermint. This native plant is mostly known for its silvery-green leaves that lighten up drab garden corners, and its late-blooming flowers, which are magnets for bumblebees. But mountain mint also has hollow stems for sheltering native insects, and its fragrant leaves are naturally resistant to deer and rabbits.

Staghorn Sumac (Rhus hirta)

Many gardeners consider staghorn sumac to be a nuisance, but there are a lot of reasons why you may want to keep this native plant around. Its stems provide habitat for pollinators, it attracts birds like goldfinches, and its berries are edible for humans too. Just don’t confuse staghorn sumac with poison sumac (Toxicodendron vernix), which can cause a nasty rash!

How to Maintain Plants for Stem-Nesting Bees

Choosing native plants that attract stem-nesting bees is just the beginning. But if you want your native plants to provide the most benefits for bees and other pollinators, it pays to understand a little bit about the lifecycle of native bees so you can ensure your plants are available when pollinators need them.

Native bees typically lay their eggs in hollow or pithy plant stems sometime between spring and fall—depending on the bee species. The parent bees then seal up the plant stems with plant debris, and the baby bees spend the winter inside the stems and emerge sometime between spring and fall of the following year.

Because baby bees spend so long inside plant stems, it’s important to leave at least part of the stems intact until the bees emerge. You can either do this by leaving the plants as-is and not pruning them at all, or you can prune the plant stems a little higher than you normally would to provide more space for the bees. Cutting stems about 8 to 24-inches above the ground usually works quite well!

Once the plant fills in in summer, you shouldn’t be able to see those longer stems at all. However, if you have neighbors who aren’t a fan of the “wilder” garden look, you can add “pollinator garden” signage to make this pruning style look a little more intentional. Alternatively, if you need to cut the stems shorter, pile the stems you remove into a loose brush pile in an out of the way corner of your garden, or weave them together to create a loose fence or dead hedge so they can still support slumbering bees.

Pruning stems a little longer every year and allowing this plant stubble to naturally degrade into the soil can support generations of pollinators to come. If you want to do even more for native pollinators, add additional native plants to your garden, choose organic growing methods as often as you can, avoid pesticides, and wait until spring temperatures are consistently in the 50s to rake old leaves out of your flower beds!