Pillars of the community

With winter approaching, most flowers have disappeared from the garden. One family of flowering plants, though, keeps on giving. Asteraceae, the aster family, competes with the orchids for the most populous of all plant families. Flowers for pollinators aren't the only ecosystem services they offer. Lettuce, dandelions, thistles, dahlias, zinnias, and marigolds are all members of this vast tribe.

 

Black-eyed Susans are in the Aster family

    Most flowers in this family are daisy-shaped, from the tiny flowers of goldenrod to huge sunflowers. An older name for the family is Compositae, because each blossom is a composite of many smaller flowers. What looks like a petal of a daisy flowers is actually an individual ray flower. The central disc, where the seeds develop, can comprise thousands of tiny flowers.

 

The central disc of a daisy offers multiple flowers for pollinators to visit

     Walking around the garden this week, I could still spot the brown and black flower heads of asters (Symphyotrichum spp.), black-eyed Susans (Rudbeckia hirta), coneflowers (Echinacea purpurea) and oxeye sunflowers (Heliopsis helianthoides), all North American natives in the Aster family. Flowers of sneezeweed (Helenium autumnale), another cousin, were still bravely opening after a hard frost earlier in the week. I aim to have something blooming for foraging insects throughout the growing season, but this perennial’s performance exceeds expectations.

Sneezeweed flowers opening

    It’s good to have these Aster family members in the garden because they offer a lot to insects and birds. The Lady Bird Johnson Wildflower Center recently zeroed in on the contributions of sunflowers to Texas’ ecology. Sunflowers don’t just provide plentiful nectar and pollen for pollinators and beneficial insects. Extrafloral nectar exuded from stems attracts ants. Beetle larvae over-winter in sunflower stalks. Even wide sunflower heads benefit wildlife by providing cover for quail and grouse chicks learning to forage for food.

Sunflowers offer both food and shelter for native insects-photo Pudelek

    Sunflowers may still be blooming in Texas. Here the blooms are gone. Massachusetts has fewer native sunflower species, but in the cold months it’s easy to observe birds feeding off seeds of daisy-shaped flowers of Asteraceae. In my yard, they like oxeye sunflower seeds and the fat seed heads of coneflowers. I haven’t seen any goldfinches lately—they’re not frequenting my thistle (nyjer) seed feeder--but if some stop by this winter, I hope to see them perching on the coneflower heads I’ve left standing.

    Of course, the Aster family isn’t exclusively altruistic. I notice how good the flowers are at recruiting passersby to transport seed to new locations. A pappus, a hairy or bristly structure, surrounds each fruit and helps it attach to fur or clothing or be wafted by the wind. Picture a dandelion head that releases its seeds to the breeze.

It's easy to see how thistle seeds hitch rides

    I’m determined to grow some annual sunflowers to maturity one of these years. So far my seedlings have consistently been bitten off at soil level before their stems get woody. I blame squirrels. 

A futile attempt to protect a sunflower seedling

I have a “pest-control pop-up,” a 3-foot tall tent made of fine mesh fabric on a flexible frame, that I hope to deploy next spring. Maybe if I sow the seeds and cover the area with the well-anchored tent, I can foil the dastardly sprout-eaters. Hope springs eternal.