No, this poster is not an advertisement to plant more thistles! As part of a class on the need for pollinator habitat, it provoked questions and the rethinking of some old ideas.
A patch of any kind of flowers covered with bees and butterflies is a bit like a soda fountain or candy counter jammed with kids. Pollinators choose flowers that are close by, abundant, and shaped so their tongues can reach the rich reward inside—nectar! Flowering weeds—what we gardeners sometimes define as a “plant out of place”—fit all these requirements. And so, pollinators discovered the virtues of flowering weeds millennia ago.
Maybe it’s time to take a new look at your lawn and garden weeds, through the lens of these creatures who are responsible for so many of the fruits, vegetables, nuts, seeds, and oils we eat. Maybe you, too, will discover the virtues of weeds already valued by our pollinators.
What pollinators need
All 4000 native bee species, as well as imported honey bees, depend on flowers for food! They get carbohydrates from the sugary nectars and proteins and fats from flower pollen. Moths and butterflies also require the foliage of specific host plants, in addition to their flowers, to provide food for their hatched butterfly and moth eggs.
Flowering spring “weeds”
With the arrival of spring, early-emerging solitary bees, such as the mason bees, go to work pollinating berries and tree fruits. Mated bumble bee queens are coming out of hibernation to begin nest construction and egg laying. Perennial honey bee colonies build up their populations from the 10,000-strong winter clusters to mighty summer-foraging forces of 50,000 or more!
Many winter- and early spring-flowering weeds provide these pollinators much-needed food when little else is in bloom. Purple deadnettle (Lamium purpureum), henbit (Lamium amplexicaule), and dandelion (Taraxacum officinale), for example, are important nectar and pollen sources.
Flowering fall “weeds”
Fall is an equally busy feeding time for our pollinators. Wasps and hornets seem to know that their nests will soon be empty. Bumble bees are rearing queens. Honey bees are filling hives with honey they will need to survive the winter. They’re also rearing important winter bees with special fat body glands that are repositories of nutrition for babies that will hatch after the winter solstice.
Fall-blooming asters (Symphotrichum spp.), goldenrods (Solidago spp.), Joe Pye weed (Eutrochium ssp.), and ironweed (Vernonia, spp.)—all native plants that are often treated as weeds—provide significant staples at a time of frantic pollinator feeding when other blooming plants are in short supply.
A special note on butterfly weed vs. butterfly bush
Ironically, the plants with “weed” in their common names, milkweed and butterfly weed (Asclepias spp. and A. tuberosa), are the essential host plants required for Monarch butterfly reproduction. But, the foliage of butterfly bush (Buddleia spp.) is of no value to any moth or butterfly in the United States. Yes, butterfly bush flowers provide nectar, but the plants escape our landscapes and show up unbidden in the wild as plants out of place!
Is your landscape a food desert to pollinators?
Or does it include a smorgasbord of useful, attractive flowering plants? Adding native flowering annuals, perennials, vines, shrubs, and trees to your yard will provide foliage for butterfly and moth larvae, as well as flowers for all pollinators. In your lawn, white clover (Trifolium repens) blooms provide nectar in summer (and as a bonus, clover along with your grass clippings may put enough nitrogen back into the soil to fertilize your lawn). Richard Orlando, in Weeds in the Urban Landscape: Where They Come From, Why They’re Here, and How to Live with Them, notes that other low-growing flowering plants, such as thymes (Thymus spp.) and self-heal (Prunella vulgaris), are lovely and useful additions to a grass lawn.
No one can—or should—tell you which plants are weeds and which are not. Of the uninvited guest plants in your yard, you decide: stay or go? Plants such as the early spring weeds can stay but not be allowed go to seed. Some may get to grow at the edge of the lawn. Some may be treasured native plants.
Options, decisions, and responsibilities abound. Just remember to use your pollinator lens from time to time when you head out to the garden to weed. Remember what A. A. Milne, the creator of Winnie the Pooh, says: “Weeds are flowers, too, once you get to know them.”
Article written by Diane Almond, Extension Master GardenerSM Volunteer.
For more information
Gardening for Pollinator Super Heroes!
by NC Cooperative Extension
Orlando, Richard. Weeds in the Urban Landscape: Where They Come From, Why They’re Here, and How to Live with Them. Berkeley: North Atlantic Books, 2018.
(Although the plant list is specific to California, the history, discussion on IPM, and notes on many plants are appropriate for WNC.)