Asters for Fall
10/16/2022 11:35 am
Asters for Fall
The common name “aster” covers a large group of plants with daisy like flowers. Many will bloom in both spring and fall, but our focus here is on the fall stars of the garden.
Fall asters are the dominant bloom this time of year. They thrive in cooler fall weather and many can take light frosts with aplomb. Here we take a look at perennial mums, sidestepping the florist mums that are ubiquitous in baskets this time of year (some of which might survive a year or two in the ground).
Fall asters are important pollinator plants. One thing to think about when planting a fall garden for pollinators is to mix flower sizes within a species. Smaller asters feed pollinators with shorter tongues than larger asters. Also, while double flowers are pretty and are fine to have some of, pollinators struggle to sip from them.
Medium to Large Flowering Asters - The Glamour Gals of the Garden
Chrysanthemum ‘Sheffield Pink’ (an apricot shaded pink) and ‘Ryan’s Pink’ (a clear pink to lavender) are taller asters that bloom October through November in full to part sun. They are spreaders that light up the fall garden. Both pull out of the ground easily with roots, ready to plop in an empty spot elsewhere. For the best effect, you will want to halve these in height mid-summer, once and maybe even twice if the growing season begins early. Otherwise they will flop over after the first hard rain. These live into late November, until the first hard frost unless heavy rain smashes and rots them. C. ‘Ryan’s Yellow’, a soft bright yellow, is another delightful color option for the garden. C. 'Ryan's Yellow' and C. 'Ryan's Pink' have been known to mess around with each other and create an interestingly colored array of babies.
Symphiotrichum oblongifolius (previously Aster oblongifolius 'Jane Bath’) has been a delight in my garden for 15 years. It’s a dependable late fall bloomer with cheery mid-sized blue-violet blooms with narrow petals. It tops out at close to 3’ high if you never cut it back, but if you do give it a cut or two in summer, you can keep it from towering over shorter perennials. These are just starting to bloom in earnest this second week of October and will keep going and going. They also spread well, but pull up easily.
Symphiotrichum georgianum is our native woodland aster. Featuring large violet blooms this is worthy for sunny spots. Cut it back in half or so in midsummer to keep it smaller and less floppy and it will reward you with close ups of butterflies and bumblebees. Or let it reach it’s full four feet in a meadow and watch from afar.
Small Flowering Asters - The Quieter Feeders
Symphyotrichum laterifolus ‘Lady in Black’, sometimes called the Calico Aster, blooms from late September to early November. Its label calls for full sun, but don’t tell mine. It grows in dappled shade and blooms prolifically. The flowers are small with rosy centers. This cultivar has blackish leaves which gives it some pop in a shadier spot.
Aster ageratoides ‘Ezo Murasaki’ is a low growing spreader that features small bright violet blooms. It prefers full sun. It’s one to watch for aggression. My solution was to abut it against the driveway on one side and on the other side with C. ‘Sheffield Pink’, which is also a spreader. This year it looks like ‘Ezo Murasaki’ is winning the duel. And it is growing in the driveway crevice too.
Then there are your “false asters,” plants with aster like flowers.
Kalimeris integrifolia sports flushes of large button sized white blooms in September to October (especially if you remember to give it a cutting back after the spring blooms).
Kalimeris pinnatifida gives its best show for me in fall, though it is no slouch in spring either. It sports vigorous double white blooms in mid-October, outperforming K. integrifolia. I do notice less pollinator action on K. pinnatifida and have started to pull some up to give the adjacent single flowering Kalimeris more room.
A favorite which also reblooms is Kalimeris pinnatifida ‘Shogun’ or yomena ‘Shogun’ (those darn botanists throwing their darts). Low growing variegated foliage hugs the ground and the blooms are a light lavender. The variegation fades through summer and is barely noticeable now. In between blooms until the last blast of heat gets it, it appears to be a pretty variegated ground cover.
Gymnaster savatieri ‘Edo Murasaki’ aka Kalimeris incisa is a deep purple form that blooms in fall. It is a low growing clumper that has done far better for me in spring than fall. Might be time to divide it.
There are many more choices of asters available. The only certainty is that no fall garden is complete without some.
- Liane Schleifer