Share this article

print logo

Great Gardening: Keep the bees, butterflies and wasps coming with a healthy pollinator garden

Most people have heard something about the threats to honeybees, butterflies and other pollinators and many want to do something about it. One result is many new pollinator gardens, in the city and in the country, filled with nectar-rich flowers and plants that support caterpillars.

But what do you do in late summer with your pollinator garden? When can we clean up the garden and do no harm? How is the timing different from our traditional landscaping practices? Let’s start with the poster-child for threatened species, the canary in the coal mine: the monarch butterfly.

What to do with the milkweed

I asked Dave O’Donnell, King of the Monarchs (the passionate educator from Eastern Monarch Butterfly Farm), how long should we keep the common milkweeds in our garden? When don’t the monarch caterpillars need them anymore? His response: “You could pull them out at the end of September if they’re really bothering you ... but first check for any stray caterpillars. If the plants are not a huge problem, definitely by the middle of October.”

He reminds us that the common milkweed (Asclepias syriaca) is the only aggressive one. It spreads underground by rhizomes – the reason that I personally look forward to yanking some of them out of the garden. Other milkweeds are even more beautiful, easily managed and better for monarch caterpillars: the native Swamp Milkweed (Asclepias incarnata) and Poke Milkweed (Asclepias exaltata). The smaller Butterfly Weed (Asclepias tuberosa), found in most garden centers, sometimes sports eggs or feeds a few caterpillars, but has less overall value.

While you’re deciding what to pull or keep, you should recognize two plants with some milkweed-like features: Swallowwort (black or pale) is a widespread non-native invasive plant that should be pulled; sometimes confused with milkweed because it also has large pods. Monarchs mistakenly lay eggs on them and do not survive. Dogbane (Apocynum cannabinum) is a non-harmful native plant with milky sap; easily confused with milkweed. It is not helpful to monarchs but does host some other moths and butterflies.

Keep the nectar coming

From the point of view of the birds, bees, and their kin, we all tidy up our gardens way too soon. If a flower has seed-heads, birds appreciate them well into the winter. Bees continue to harvest nectar for making honey – their winter supplies as well as their treasure for humans – until the weather turns cold. So don’t cut back flowers until they are brown and finished. As O’Donnell put it, “Mother Nature is a pretty good indicator of when nectar flowers are no longer necessary. When you look into the fields and see the goldenrod and New England asters turn brown, usually after a frost or two, you can cut back your nectar flowers – usually mid-October.”

Our plant choices also make a difference what the pollinators can find. Beekeeper Erin Masterson, daughter of Mike Masterson (Masterson’s Garden Center, a primary source for beekeeping supplies and information) recommends native plants wherever possible. “Plant for bloom times throughout the entire growing season, from early through late,” she said. She mentioned Serviceberries (Amelanchier) as well as dandelions as sources of spring nectar. This season she’s noticing the bees going crazy for Echinacea (Coneflowers) and salvias. I also recommend Japanese anemones, turtleheads, asters and goldenrod. At Masterson’s Honey Festival (Oct. 1 and 2) guests will taste honey from a range of plants including early blooming apple trees and late-season goldenrod as well as the invasive Japanese knotweed.

Spread the pollinator plants

Some pollinator-pleasing annuals self-seed (cosmos, fennel, dill, love-in-a-mist, Dame’s rocket, forget-me-nots). So let them. Now, rather than cut them back, let the seed heads stand; expose some soil in their vicinity; recognize seedlings in spring and weed around them. In September you can plant native perennials such as my favorite: New York Ironweed (Vernonia). Add and maintain native plants such as Lavender beebalm (Monarda fistulosa) in a meadow if you can. In your yard include more larval food plants for caterpillars: turtlehead, wild lupine, willows, oaks, hackberry, Dutchman’s pipe, Spicebush (Lindera benzoin). Then tolerate some holes in the leaves.

I often ask experts what plant they wish to see used more often. Native plants expert Lyn Chimera of Lessons from Nature ( answered easily: “Mountain mint (Pycnanthemum) species – they get covered with all sorts of pollinators.” On a mountain mint all day you’ll see honeybees, cuckoo bees, Halictid (sweat) bees, Sphecid (thread-waisted) wasps, bee flies, pearl crescent butterflies and more.

End entomophobia

While so many good folks are trying to help the pollinators, one giant problem remains. We have a culture of “entomophobia” – hatred or fear of insects. Perhaps it comes from lack of experiences in nature, and a society that fails to foster much wonder, reverence and compassion for other beings. Many youths and adults commonly kill insects they can’t even name and that are not dangerous or harmful. Some gardeners, homeowners, and even some farmers react to insects with knee-jerk spraying of pesticides before considering alternatives and consequences. Most scientists who study bee colony collapse disorder, the plight of the monarchs (and many other endangered species) connect those problems at least in part with some pesticide uses. We need attitudinal and behavioral changes.

Meanwhile what we can do: Keep those pollinator gardens going.

Sally Cunningham is a garden writer, lecturer and consultant.

Here are some of Erin Masterson’s tips for a pollinator garden:

• Plant in masses of one type of flower; bees love big areas in bloom.

• Include plants with clusters of flowers on a single stem such as lavenders, salvias, agastache, Culver’s root (Veronicastrum) and Lamb’s ears. “The bees like the convenient shopping,” Masterson said.

• Many native bees are ground dwellers so leave large patches of soft, exposed soil for their nesting.

• Provide some bee houses for native bees (orchard bees, alfalfa bees) since there are fewer dead trees or outbuildings these days.

• Let some cool season veggies (broccoli, cauliflowers, lettuces) bolt or go to seed. “Bees love broccoli flowers!” she said.

• Where there are no natural ponds or streams (or they are dried up) provide water in shallow bowls – especially near swimming pools that we’d prefer they not visit.

There are no comments - be the first to comment