Late bloomers
Deciduous trees aren't the only source of autumn colour, writes Lynda Hallinan. Some summer stars are simply fashionably late to the party. .
Lynda Hallinan on the beauties that herald late summer and early autumn
Autumn is a slow-burner in my Hunua garden. Further south, the end of summer is clearly signalled by the forest fires of deciduous foliage but, here in the north, the season’s change is a bit of a damp squib. I can only say for certain that autumn has arrived when the fog rolls up our valley at dawn each day and my slippers end up soaked in dew whenever I need to walk across the lawn in the morning.
Over the next few weeks, the pin oaks and liquidambar trees that line our driveway will start to colour up, and the swamp cypresses ( Taxodium
distichum) in our wetland are reliably impressive as autumn gives way to winter, but in the meantime there’s one last colourful hurrah to enjoy.
This in-between season, when the garden clings on to its last vestiges of summer glory, goes one of two ways. In a good year, summer daisies such as rudbeckias, dahlias and heleniums are still going strong when the leaves start their chameleon change, but in a bad (wet) year, they flop in a sodden heap or are felled prematurely when early frosts strike this month.
There’s no coming back from those first frosts, which catch me out every year. Despite the best of intentions, I never get around to taking coleus cuttings (to overwinter indoors in pots) before Jack Frost wipes the lot out, along with the zinnias, cosmos and other tender annuals.
Looks can be deceiving, however. Take the flashy Summerific hibiscus range from Proven Winners. Bred in America but with bold, Pacifica-style blooms, they couldn’t look more tropical if they tried. Yet, because they are deciduous, they can cope with temperatures as low as -4°C.
My favourite is ‘Midnight Marvel’, as everything is showy about this plant. It forms a compact clump of dark mahogany foliage, to 1.2m tall, topped with enormous, silken red flowers as wide as my handspan. The flowers only last a day or two but each stem is topped with a cluster of buds and, when the petals fall, the vibrant lime-green calyx is almost as attractive, with a form reminiscent of lime green hellebores in winter.
Although hibiscus are generally thought of as summer flowers, these hardy varieties don’t start to bloom until February, when most summer flowers have done their dash. Plant in full sun at the back of a border or in a large container; in pots you can keep the display going for longer by bringing your containers indoors when frosts threaten.
Summerific hardy hibiscus die down completely in winter, which means they don’t end up with woody, lanky legs like their tropical cousins. Mulch for extra insulation over their first winter and be patient in spring, as they have a reputation for being slow to sprout. For this reason, it’s worth marking your plants with a stake so you have a general idea of their whereabouts.
In my garden, I grow ‘Midnight Marvel’ in a Gothic-themed garden around a graceful grove of purple Japanese maples ( Acer palmatum ‘Red Emperor’). Its foliage goes nicely with bronze-foliaged ‘Indian Summer’ alstroemerias, flamboyant coleus, purple salvias, and variegated purple, silver and cream bugleweed ( Ajuga ‘Burgundy Glow’ and its garish little sister ‘Multicolor’).
Tardy but terrific perennials mark the end of the golden weather with one last hurrah before it's time to bed down for winner.
If you are familiar with any of these plants, you can probably guess that this is no good taste garden, especially when ‘Brilliancy’ sedums add their hot pink blooms to the mix in early autumn. Unlike Sedum ‘Autumn Joy’, with its sophisticated rusty colours, ‘Brilliancy’ is almost fluorescent pink.
This year, my Gothic garden is also sporting tall black pokers of annual ornamental pearl millet. Even before it flowers, Pennisetum glaucum ‘Purple Majesty’ (from Puriri Lane Nursery in Drury) is a real looker, with strappy, 1m tall mahogany foliage that’s the spitting image of sweetcorn dyed black.
The poker flowers – pointy plumes as dark as pinot noir – are great for picking and for snacking on! When mature, sweet, nutty-flavoured, shiny pink seeds form along the length of the spikes. These are edible, if you can (a) be bothered stripping them off and (b) beat the birds to them.
Pennisetum glaucum ‘Purple Majesty’ is a striking companion for perennial salvias in shades of deep purple and burgundy, such as ‘Love and Wishes’, ‘Amistad’ and ‘Black Knight’.
Says British flower gardening guru Sarah Raven of ‘Love and Wishes’, “I love this plant for its very long flowering season and the beautiful contrast between the calyx and its velvet flower.” ‘Amistad’ and ‘Black Knight’ are similarly blessed with dark calyces, so even when all the petals have fallen, the plants still hold their own in a border.
Salvia ‘Love and Wishes’ is just the right shade of deep burgundy to tone in with, and tone down, an eclectic assortment of Main Street coleus, and to bring the best out of the dusky pink Heuchera ‘Bronze Beauty’. This heuchera (from Pepper Tree Nursery in Thames) is new to me but I suspect it will become a shady favourite.
I love its description on the website heucheraholics.co.uk: “Beautiful, architectural, deeply cut foliage of bronze and cappuchino with a slighty hirsute dusty look. A great statement plant.” Indeed, it is.
The foliage is flesh pink on top, but a darker shade of purple-pink on the underside, and in summer there are tall cream flowers. Pepper Tree’s Trish Uffindell says unlike many heucheras, this variety hails from the southern United States and, as such, tolerates more heat and humidity than most.
That’s lucky, because neither heat nor humidity were in short supply in summer – in fact, it was the hottest summer on record, according to Niwa’s official statistics. But at least it wasn’t bone dry in Hunua. By the end of February, 219mm of rain had fallen (compared to our local 29-year average of 92.6mm), which kept my
Cercis canadensis ‘Forest Pansy’ trees – not to mention the fruitful purple-leafed nectarine ‘Mabel’ – actively growing and producing more of their famous dark red new foliage, rather than developing the usual copper tones at the end of summer.
With its heart-shaped leaves and rich foliage colour, Cercis ‘Forest Pansy’ is a deservedly popular small tree, but I think the new weeping form ‘Ruby Falls’ is even better. It has cascading branches with the same deep colour and makes an instantly captivating specimen tree. I’ve tucked one into my woodland garden, in a sunlit vacancy created by the felling of a storm-split tree. (Cercis doesn’t colour up as well in deep shade.)
Autumn foliage can be just as striking at ground level as in the tree tops overhead. The leaves shown above include ajuga, berberis, bergenia, begonia, coleus, cotinus, hibiscus, physocarpus and Cercis 'Forest Pansy'.
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My Cercis ‘Ruby Falls’ tree is flanked by burgundy-leafed ‘Britt Marie Crawford’ ligularias and the so-called tractor seat variety, Ligularia reniformis. Although prized predominantly for their foliage, in autumn they also sport cheerful golden daisy flowers. Gardeners with subtle tastes tend to chop these off, believing they detract from the foliage display, but I can’t see the point. Why do we savour some sunshine-yellow flowers – coreopsis, helianthus, marigolds, rudbeckias, sunflowers and zinnias – yet shun others? It makes no sense.
You know what else makes no sense? Sowing red or bronze sunflowers in a big garden. ‘Moulin Rouge’ and ‘Evening Sun’ are fabulous cut flowers but in the garden their recessive colour makes them all but disappear when viewed from a distance.
Similarly, for impact in the garden, the red helenium ‘Lord of Flanders’ (from Marshwood Gardens and Puriri Lane Nursery) is no match for the highly recommended orange variety ‘Moerheim Beauty’, or bright golden ‘Butterpat’, but it’s so ravishing in a vase that it seems churlish to quibble.
Every gardener should plant a few heleniums, not just for their long, late show of colour, or because honey bees and bumblebees go bonkers for them, but because, once established, they stand tall on strong, 1-1.5m stems. They are lovely in their first year, stunning in their second and utterly gorgeous by their third season, at which point you can start dividing up the clumps with a spade.
Heleniums need full sun to perform at their best, whereas bergenias bring a touch of glamour to shade, with their big, glossy, tongue-like leaves.
I’m developing an obsession for these hardy perennials, which began with Bergenia ‘Wanaka Wine’. This new release has huge leaves that colour up from green to merlot, with hot pink flowers from late winter.
I’ve also planted the little hairyleafed Bergenia ciliata, a gargantuan white form from Pepper Tree Nursery and a dozen or so of Terry Hatch’s seedlings from Joy Plants – he’s been tinkering about breeding bergenias. I’m hopeful they’ll thrive where previous attempts to grow Chatham Island forget-me-nots have failed.
Last but not least, I think it’s time to rectify my unintentional snubbing of autumn-flowering asters. In 20 years of writing about gardens, they have rarely rated a mention in any of my columns, even though I’ve planted them in every garden I’ve ever had.
Botanists have reclassified most asters as Symphyotrichums but I doubt that name will ever catch on. We’ll always know them as asters: easy, adored by bees, upstanding and great for picking. Plant in full sun, in free-draining soil, and deadhead the old stems for a longer display.
At Marshwood Gardens in Invercargill, Geoff Genge has a wide selection, from famous lavender-blue
Aster x frikartii ‘Mönch’ to pearly white ‘Snowball’. There are small, medium and large cultivars, such as dainty, 40cm tall ‘Little Boy Blue’ for the front of borders; purple-red ‘Winston S. Churchill’ for the middle; and, for height at the back, a 1.5m selection of ‘Harrington’s Pink’ that Geoff jokingly named Pink Mystery.
And don’t forget about the closelyrelated China asters, Callistephus
chinensis, like long-stemmed ‘King Size Apricot’ from Kings Seeds. I’ve long hankered after this fully double delight with pale apricot petals, and this year I’ve struck the jackpot. Sow in early November for autumn cutting.
In autumn, when everything else is either catching fire and making a spectacle of itself, or slumping to the ground in a tired heap, asters add a touch of fresh, gentle femininity and pastel cottage charm, reminding us that spring is just a winter away.