Aromatic aster welcomes visitors in a dramatic seasonal display along this home entry. Mass planting complements the modern, linear pathway lending a soft but formal impression.

As keystone plants, native asters are pollinator superfoods, scoring top marks for hosting high numbers of both lepidopteran (moths and butterflies) and specialist bees. The late blooms of asters provide critical forage for migrating monarch butterflies as well as new queen bumblebees bulking up for winter hibernation—and they’re year-round bird feeders.

Aromatic aster (Symphyotrichum oblongifolium) and blue wood aster (Symphyotrichum cordifolium) are two adaptable, garden-worthy native asters. Both add beauty and valuable late-season forage to the pollinator garden. Dive in below to learn about their different growth habits and uses in the landscape. Photos are from my garden design projects, and this piece was adapted from a contribution to The Buzz—the newsletter of the Pollinator Pathway—that I made this spring.

Aromatic aster (Symphyotrichum oblongifolium)

Aromatic aster has a mounding and tightly branching form and will spread slowly by rhizomes. It is easily grown in average, dry to medium, well-drained soil in part to full sun. It does well in sandy or clay soils and generally tolerates rocky soils and drought. The species and a selection called ‘October Skies’ will both grow 25-36” tall and 40-50” wide depending on site conditions. ‘October Skies’ often displays a more shapely habit and out-performed the species in pollinator visits in the Penn State Pollinator trials. While aromatic aster is typically reliably self-standing compared to other large asters, it can flop open after many years of establishment and benefits from an optional mid-season cutback depending on aesthetic preference and garden conditions.

While this late blooming aster naturally ranges north to south from Pennsylvania to North Carolina and west to eastern Montana and western New Mexico, it will reliably grow into southern New England. Although naturally associated with calcareous conditions, it grows well in garden soils with a wide pH range.

Species aromatic aster blooms alongside orange coneflower (*Rudbeckia fulgida var. fulgida*) and brown-eyed Susan (*Rudbeckia triloba*) in this mixed prairie-style front yard garden. Floriferous selections extend the seasonal display into late October while providing important nutrient energy for both southward migrating monarchs and native bees preparing for winter hibernation. Butterfly milkweed (*Asclepias tuberosa*), little bluestem (*Schizachyrium scoparium* ‘Standing ovation’), northern bush honeysuckle (*Diervilla lonicera*), and a young oak sapling join for an ecologically powerful planting combination. Many perennial species were planted in small sizes in the spring before this photo was taken demonstrating the often rapid growth possible in a single season. Aromatic aster’s position in full sun encourages a dense growth habit despite this being an unnamed selection.

The leaves and flowers of aromatic aster have a pleasant minty aroma that often catches the attention of passers-by. Short and long-tongued bees as well as small to medium-sized butterflies and other pollinators appreciate the fall nutrient resources of pollen and nectar, and the foliage hosts caterpillars of the silvery checkerspot butterfly and many moths. The flowers display purple ray florets and yellow central disk florets. Note the changing colors of individual disk florets as they mature from yellow to bronzy purple.

Intermittent sweeps of aromatic aster create a soft, low edge on both sides of these deep, lush garden beds off the back patio.

I sited this sun-loving aster in mass for a formal effect in a front lawn conversion to native plants. People and pollinators flock when these are in bloom.

Aromatic aster ‘October skies’ decorates the front entry to this home with billowy abandon. Blooming after Joe-pye weed (*Eutrochium dubium* at right with pink inflorescence) and alongside ‘Fireworks’ goldenrod at left, this planting replaces former non-native species and boosts wildlife value and seasonal interest. Moss phlox cultivars (*Phlox subulata* cvs) spill over the front edges for early spring blooms and ground covering functionality.

This tough perennial plant combination in a driveway island takes advantage of a simple plant palette. Layered beneath an existing evergreen specimen, the ‘October skies’ selection of aromatic aster provides late season interest after spring blooming golden ragwort (*Packera aurea*) and the summer inflorescence of broad-toothed mountain mint (*Pycnanthemum muticum*). Deer-resistant, salt tolerant, and rapidly-growing, this combination helps to compete with existing undesirable species in the sunny space. Asters here only need occasional pruning to tidy the edge.

Welcome home to this conservation landscape on the Lower Merion and Narberth Pollinator Pathway in Penn Valley, Pennsylvania. An elegant combination of woody and perennial plantings for wildlife value, resilience, and aesthetic sense of place greets visitors at the driveway entrance. If the Earth is a garden, this property exemplifies a valiant and landscape-wide effort at ecological stewardship. In fall, aromatic aster blooms beneath the mailbox complemented by the elegant fall color of fragrant sumac (*Rhus aromatica* ‘Gro-Low’) at left. Spring and summer perennials in the space include eastern bluestar (*Amsonia tabernaemontana*), hoary skullcap (*Scutellaria incana*), wild bergamot (*Monarda fistulosa*), wrinkle leaf goldenrod (*Solidago rugosa* ‘Fireworks’), and flowering spurge (*Euphorbia corollata*). Winterberry holly (*Ilex verticillata* ‘Red Sprite’ with red berries) and American holly (*Ilex opaca*, a large and stately evergreen) anchor the backdrop along a simple split rail fence while smooth sumac (*Rhus glabra*) shows off bright red foliage on tall lanky stems. This combination proves drought, deer, and salt-tolerant for this south-facing roadside driveway entrance and reflects the plant diversity made possible by lean soils.

Aromatic aster ‘October Skies’ exhibits a tight form when young as shown in this first year patio garden in part to full sun. Asters pair beautifully in combination with native grasses like little bluestem (*Schizachyrium scoparium* ‘Standing ovation’)—at left in this garden. ‘Standing ovation’ displays an orangy-red fall hue and generally stands nicely through winter. Both plants do well in lean soils with little fertility and good drainage. Additional planting partners in this space include Eastern columbine (*Aquilegia canadensis*), cardinal flower (*Lobelia cardinalis*), wrinkle leaf goldenrod (*Solidago rugosa* ‘Fireworks’), white-tinged sedge (*Carex albicans*) and more. Despite a layer of first year wood mulch while new plantings are growing to full size, this garden will not need mulch going forward—an important theme for sustainable gardens and a break from traditional yearly wood mulch applications which otherwise limit re-seeding and are often paired with pre-emergent herbicides—chemicals that can negatively affect soil life.

A newly planted rain garden in front of this New Jersey home intercepts rainwater from the roof to benefit the local watershed. A shallow basin was dug to retain runoff behind a raised earthen berm of soil inthe foreground. While the center basin is planted with species that can tolerate both temporary flooding and drought conditions like River birch (Betula nigra), Northern bayberry (Myrica pensylvanica), species Aromatic aster anchors the drier, well-drained berm alongside other drought-tolerant perennials like narrow leaf mountain mint (*Pycnanthemum tenuifolium*). Aromatic aster (center foreground) begins its first blooms in mid-September in this full sun garden.

A native cottage-style garden in part-sun with average soil moisture blends the use of two selections of aromatic aster—a combination of ‘October skies' and ‘Raydon’s favorite’. ‘Raydon’s favorite’ has larger flowers and often blooms approximately 2 weeks later than ‘October skies’. Including both selections extends the blooming season although ‘Raydon’s favorite’ will get much larger and sometimes benefits from early-season cutback to prevent flopping. These asters easily mix with winterberry holly (*Ilex verticillata* ‘Red sprite’ with red berries), inkberry holly (Ilex glabra ‘Shamrock’), orange coneflower (Rudbeckia fulgida var. fulgida), and American alum root (*Heuchera villosa*). Naturally-occuring white snakeroot (*Ageratina altissima* with white flowers) joins the party for a touch of welcomed wildness and additional late-season pollinator value.

Golden-crowned kinglets mainly eat insects, and asters serve them up during migration and through the winter.

Aromatic aster mixes beautifully for all-season interest in combination with Virginia sweetspire (*Itea virginica*), switchgrass (*Panicum virgatum*), blue flag iris (*Iris versicolor*), and black-eyed Susan (*Rudbeckia hirta*) in this full sun, front yard landscape. The diverse but simple grouping highlights the possibilities for compelling foliage and color combinations in smaller garden spaces.

Aromatic aster ‘October skies’ adorns the part to full sun entry gardens of a public park in southeastern Pennsylvania on the Pollinator Pathway. A mass planting on well-drained garden beds is a beautiful and easy care choice. Since aromatic aster is densely branched, it makes an effective ground cover without the need for underplantings, and it supports itself better than many taller asters that otherwise fall over or need mid-season prunings. Mass planting also has the added benefit of readability to passers by and easy recognition by caretakers in the garden. Other native species in this space include switchgrass (*Panicum virgatum* ‘Purple tears’), wrinkle leaf goldenrod (*Solidago rugosa* ‘Fireworks’), swamp milkweed (*Asclepias incarnata*), narrow leaf mountain mint (*Pycnanthemum tenuifolium*), Kalm’s St. John’s wort (*Hypericum kalmianum* ‘Gemo’) and many more.

Blue wood aster (Symphyotrichum cordifolium)

Blue Wood Aster is a woodland aster—easily grown in average, dry to moist, well-drained soils in part sun to part shade (and sometimes full sun). Growing up to 60” tall, it functions as a tall ground cover where desired. It’s a vigorous spreader compared with aromatic aster and will often self-seed with abandon in dry to moist soil conditions. Pinching back stems several times before mid-July helps to control plant height (where desired) and promote branching, and seed heads may be cut after flowering to prevent unwanted self-seeding. This species has a wide natural range east of the Great Plains except into Florida. Note the presence of this aster in the library garden in the above photos as well as the gardens below.

I let my blue wood asters go nuts around the vegetable garden and enjoy watching the pollinators in the evening sun.

Blue wood aster even seeds into my bluestone walkway - fun!

Thoughtfully vegetated spaces beneath regionally native tree canopies are called “Soft Landings” for their unique capacities to provide habitat to various life stages of wildlife like moths, butterflies, native bees, fireflies, and other insects. In addition to plants, soft landings also include fallen leaves which insulate the soil and protect and feed soil life. The presence of flowers in fall here reminds us that shady gardens can also provide beauty as well as nectar and pollen in the late season. Asters are not only keystone plants for caterpillar species but also serve specialist bees that prefer their pollen.

The prolific fall blooms of aromatic and blue wood asters intermingle with threadleaf bluestar to produce an impressive display in this suburban traffic island on the Pollinator Pathway in SE Pennsylvania. Note the deeper purple bloom color and larger flowers of aromatic aster along the front edge and the lighter, smaller blooms of blue wood aster. The traffic island was converted to native species seven years ago and shows perennials in dense combination under a honey locust tree. Late season warmth encourages continuous flowering, and the plants still buzz with bees into mid-November. Leaves from the tree in the island remain year round to create a safe space for the insects overwintering here. The prolific re-seeding tendency of blue wood aster is welcome—it spread around the island from its original position in a few short years—but it needs regular cutbacks in this public space where sight lines for vehicles dictate shorter plant height. Depending on yearly moisture conditions, plants can reach almost 5 feet in height, so these beauties get cut back at least twice between May and August in years with normal precipitation. Pruning cuts are intended to reduce ultimate plant height for the season and to shape the edge of the island. Clean edges read as intentional to passers-by, making this combination of densely growing perennials acceptable in the highly visible space. Pruning cuts also encourage denser branching and a more floriferous show in fall. Aromatic aster does not need pruning for height control and only receives aesthetic cuts where it overgrows the edges in this space. Planting partners in the island include red bee balm (*Monarda didyma* ‘Jacob Cline’), golden ragwort (*Packera aurea*), and orange coneflower (*Rudbeckia fulgida*). The characteristic deep yellow fall foliage of threadleaf bluestar (*Amsonia hubrichtii*) provides a striking complement to the late-season aster blooms.

A wide view of the traffic island showing the honey locust tree.

I hope you have as much fun as I do including these important aster species in your garden spaces! Ask for them at your local native plant retailer. They are powerhouses for wildlife and bring joy to human observers with their prolific late season blooms. Easy growing, they are good species to try if your conditions are right, and I hope you also explore the many other beautiful native asters (Symphyotrichum, Eurybia, and Doellingeria species) as your planting palette grows. Naturally-occuring species are fun to encourage in the garden too. I could go on and on… :)

Aromatic Aster and Blue Wood Aster: beauty and wildlife bounty

Landscape stewardship, Step 1: Plant a native tree