The showy flowers and berries of September remind me of ladies at a cotillion in Scarlett O’Hara’s time – the full skirts and puffed sleeve dresses, all ruffles and flounces, adorned with huge hats and jewels. Our gardens are the ballrooms, and nothing is subtle about this end-of-summer dance. Even the plants know it’s their last chance for full-out performances.
These four are among the best of the lush and lovely ladies of the final summer parties, among them stunning flowering shrubs and perennials – all hardy (even the mums).
Truly hardy mums
It’s been the fall flower question as long as I’ve answered garden questions: “Will this mum (chrysanthemum) really come back next year? Is it hardy?”
Technically we have always had “hardy chrysanthemums,” but many disappointments followed that expectation and gardeners turned skeptical. Hardy mums have sometimes survived fall planting but, like any perennial plant, they have some requirements for survival:
• Plant it in time to get the roots established, the earlier in September the better (or better yet in spring or early summer if you could acquire the plant).
• Plant it in full sun, and in good soil with great drainage. Water well until freezing time.
• Provide some winter protection: Plant it where there is good snow cover, but away from blasting winter wind on exposed sites. Leave the stems above ground for some crown protection for winter, and then mulch with 3 inches of straw or wood chips after the ground freezes.
Then the mum is hardy, except …
Some chrysanthemum cultivars became less hardy for several reasons: They were hybridized intensively in pursuit of larger flowers or more colors and some hardiness traits were lost. They were grown for the fall container and doorstep market and pushed with fertilizers and pinching techniques at the expense of much root grown. They’re gorgeous decorative plants, but perhaps short-term.
Now, however, really hardy chrysanthemums (sometimes called Dendranthemums) are available. The Zittel Farm in Eden grows and sells hardy mums– developed in Belgium – for a local nursery and for Wegmans’ landscapes. Some garden centers have offered another line called Mammoth Mums, that grow to 4 feet tall with hundreds of flowers per plant and cute spoon-shaped petals.
A Newer ‘Igloo Series’ is amazingly florific, with less brittle branches. One area garden center has ‘Cool Igloo, Warm Igloo, Harvest Igloo.’ You may also see them marketed using a ‘Rozanne & Friends’ label: Nothing to do with a TV series; everything to do with pairing with the lovely ‘Rozanne’ perennial geranium and other valued perennial friends.
Huge hydrangea flowers
And they’re not blue, nor “Endless,” and they only started flowering a few weeks ago. This month you are seeing spectacular panicle hydrangeas (Hydrangea paniculata), most of which grow 6 to 8 feet tall – although some now come as dwarf cultivars such as ‘Little Lime, Bobo’ and 'Little Quick Fire.'
These are the easy hydrangeas once you plant them well. They are not fussy, and bloom dependably in the second half of summer. They have few requirements: at least partial sunlight, water while they become established and room to grow. The flowers are mostly white or greenish-white to pinks, some two-toned, mostly pointy, and up to 8 inches long – often used in wreaths and dried arrangements.
There is nothing not to like about this plant. You can plant them now or next spring – but either way, go to see them now in a nursery, garden center, public garden or park, while they are glorious.
With the name Hibiscus, it’s no wonder that people don’t expect these gorgeous plants, with 6- to 8-inch diameter flowers, to be hardy. Hibiscus is a large genus (about 200 species) that includes the tropical plants (sometimes houseplants) we love, and Rose of Sharon.
But the Hardy Hibiscus, aka Common Mallow (Hibiscus moscheutos), now seen flowering, is mostly hardy here in USDA Zones 5 or 6. They need full sun and moist soil during the growing season. They may attract Japanese beetles, but if that happens it’s still worth your time to pick them off.
The other risk: In winter the tops become sticks that appear dead – and remain so nearly all spring. I have seen tiny growth appear as late as June 1, and still enjoy a full-sized flowering plant in August. Don’t give up on them. Some gardeners may prefer over-wintering them in a basement or cold greenhouse, for faster start and earlier flowers in summer.
While it won’t stop traffic from 30 feet away, the shrub Callicarpa will certainly produce comments and inquiries from anybody who walks by it in September or later. The native plant, Callicarpa americana, grows from Maryland southward and is probably not hardy in WNY gardens – but try it if you have a protected microclimate.
Choose whichever cultivars you can find, but compare the labels to see the mature size. The plants die back nearly to the ground, depending upon the winter.
I shape mine (casually) in late spring once I see where the leaves are coming in. I adore mine, a tidy 4-foot plant in part shade that produces the most gorgeous lilac/purple berries in August – but I wish I had planted it in at least partial sun to get even more berries.
Several cultivars have emerged lately with pink to deep purple berries, some with wine-colored leaves. Your garden center may have ‘Profusion, Purple Pearls’ or a new Proven Winner called ‘Pearl Glam,’ but whichever you find, do put one in your landscape.
All lists leave out somebody’s favorites, especially this short list of late summer beauties. Another time we’ll talk about dahlias (and how to keep them over winter), goldenrod (which is not what makes you sneeze) and all the beautiful perennials like Monkshood and Japanese Anemones that are blooming all month and next.
For now, applaud the beautiful dancers who dressed themselves up so beautifully for the pollinators and for you.
Sally Cunningham is a garden writer, lecturer and consultant.