Now that I have the taxonomy issue out of my system (see last post), I can write about the asters in my garden. (As hillwards points out, “They may not be Asters any more, but they will always be asters …”). All the asters I grow except for one are Midwest USA natives and straight species. They represent a small slice of the hundreds of species and cultivars available.
I love asters because they flower freely, provide lots of fall color, and are extremely tough and easy to grow. They vary widely in the kind of environments to which they are adapted.
New England Aster (Sympohtrichum novae-angliae). This is a tall aster that likes moist soils and sun. Mine grow to 6′ and require staking even after I cut them back in late May. Next year I plan to cut them back at least twice and see where that gets me. The wild species is variable in color, and mine bloom in both a rich purple and pink. In my garden this plant gradually expands to form large clumps. New England Aster is a good flower for monarchs and other fall butterflies, and goldfinches eat the seeds.
A common dwarf variety of New England Aster is ‘Purple Dome‘, which I have growing in my back yard. In my garden it stays under 2’ tall. For me it blooms later than the species.
Short’s Aster (Symphotrichum shortii). This aster is less common in gardens, but I find it to have many virtues. Short’s Aster blooms profusely, covering itself with sky blue flowers in fall. It grows well in part shade or sun, and is generally adaptable. It can grow quite large and bushy (up to 4′), and I usually cut it back once in late May. It will self sow – if you hate pulling out seedlings you might want to cut it back before the seeds ripen.
Aromatic Aster (Symphotrichum oblongifolium). Aromatic aster is well adapted to drier, sunny spots. It also stays more compact than many wild asters and self-sows infrequently. The light blue flowers have golden centers. One of my favorites.
White Woodland Aster (Eurybia divariticus). I’ve read that this aster spreads aggressively, but that has not been my experience. In fact, I planted it years ago in a moist, shady spot and it gradually disappeared. I’ve got it growing now in dry shade, and we’ll see how it does. A low-growing aster with white flowers.
Calico Aster (Symphotrichum lateriflorum). Do not plant this aster in fertile soil and full sun. It will become a monster, more a shrub than a perennial, and self-sow aggressively. However, I have found it to be well-behaved in shade. Many tiny white flowers with maroon and yellow centers grow along horizontal stems. I like the way it looks, but I gave one to a friend of mine and she thought it was quite weedy. Especially loved by bees and other pollinators.
Crooked-Stem Aster (Symphotrichum prenanthoides). Crooked-Stem Aster likes moist soil and does well in shade. It creates an airy cloud of white to light-blue flowers.
Big Leaf Aster (Symphotrichum macrophyllum). This is another aster with a reputation for thuggish behavior. I have it in dry shade where there is plenty of competition from shrubs, and there it has spread slowly to form a nice groundcover with its large, heart-shaped leaves. Big Leaf Aster blooms earlier than most of the other asters in my garden.
These asters can be ordered on line from native plant nurseries. Also, most of the above species have cultivars which can be found in garden centers. If you feel your garden needs more fall color, it’s worth taking a look at these plants.