A wealth of late-blooming plants are bright stars of the autumn garden

In the language of flowers, or “florography”, the daisy is said to symbolise joy and innocence, two qualities that this world of ours is all too often too short of. Even non-gardeners will easily recognise the common daisy, Bellis perennis, the well-known wildflower with its jaunty central yellow button or “boss” and circlet of snow-white petals that is such a common sight in Irish gardens and roadside verges from late spring through to early autumn. Most will also remember the simple pleasure of making daisy chains as children to string around our neck.
But from a botanical point of view, the daisy family (or ‘Asteraceae’, to give it its proper name) is a vast one that’s home to many thousands more species than this one pretty wildflower, and which includes a wealth of late-blooming, garden-worthy plants that are the bright stars of the autumn garden. What they have in common is their daisy-shaped flower heads and their ability to provide plenty of food for bees, butterflies, hoverflies and many other pollinating insects, as well – typically – as a love of bright sunlight.
One of the most diverse as well as the most visually impactful is the dahlia, the undisputed queen of many Irish flower borders at this time of year. From lofty giants such as the crimson-flowered Dahlia ‘Admiral Rawlins’ to graceful species-types such as the lilac-pink Dahlia merckii, giant dinner plate-types such as Dahlia ‘Café au Lait’ and miniature pompon varieties such as the heritage variety Dahlia ‘Moor Place’, there’s something to suit everything. Dahlias are fully edible too, from their pretty petals to their fleshy tubers, which were once grown as a food crop. Just make sure to give these hungry, thirsty, sun-loving plants a prime position in the garden, and to stake, feed and regularly deadhead them to keep the show on the road until the first killing frosts arrive to cut them to the ground.
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Grown in a free-draining soil in milder parts of the country, their fleshy tubers can be left in the ground over winter so long as you make sure to protect them from sub-zero temperatures with a very thick mulch of old straw, bracken, heather or spent compost. In colder areas, cut back the plants after they die back, then dig up the fleshy tubers and store them overwinter in a frost-free shed. Just bear in mind that slug damage is often a problem, as their young shoots emerge again in late spring, so take suitable precautions.
Another supremely showy, sun-loving member of the daisy family is the perennial known as Echinacea, or coneflower, whose striking flowers can be shocking pink, electric orange, yellow or white, depending on the particular variety. Easily raised from seed sown in spring or autumn under cover and with gentle heat to give generous quantities of plants without breaking the bank (see jelitto.com), it does best mass-planted in fertile, free-draining soil in a hot border alongside ornamental grasses and other later-flowering, foliage-light perennials such as sanguisorba, Verbena bonariensis, rudbeckia and helenium that won’t cast shade on it.
Just bear in mind that not all varieties are created equal. In my own garden I concentrate on varieties of the always graceful Echinacea pallida and Echinacea purpurea, which seem considerably more reliably perennial than many of the very showy but sometimes less resilient hybrid varieties seen for sale. Their graceful single flowers are also much preferred by pollinating insects to any of the double-flowered varieties. Much like the dahlia, this supremely decorative, nature-friendly herbaceous perennial’s one great weakness is its vulnerability to damage from slugs and snails as it emerges in spring, so again make sure to take careful precautions.
The aforementioned helenium is another member of the daisy family that’s outstanding in terms of the vividly colourful flower power it offers at this time of year. Commonly known as sneezeweed, its dried flowers were traditionally used as a form of medicinal snuff, hence the name. Outstanding hardy perennial varieties include the exceptionally long-blooming Helenium ‘Sahin’s Early Flowerer’, whose brown-eyed, yellow-and-burnt-orange flowers are beautiful; the compact, very floriferous and relatively new variety known as Helenium ‘Fuego’; and the golden-yellow Helenium ‘Bluetentisch’, all of which have the distinctive daisy-shaped flowers typical of members of the Asteraceae family.
So too does rudbeckia, a genus that includes many hardy herbaceous perennial stalwarts such as Rudbeckia fulgida (black-eyed Susan), the lofty Rudbeckia laciniata, a giant suitable for the back of a large sunny border, and the eye-catching Rudbeckia subtomentosa. All have the shocking-yellow flowers typical of this genus.
Asters (Michaelmas daisies) are yet another example of a late-flowering member of the daisy family, as well as one of many whose flowering period is triggered by the shorter days of autumn, proving there are some surprising perks to those dwindling hours of daylight. Another brilliant choice for the autumn flower garden, taxonomists have long tinkered with this group of exceptionally long flowering perennials, whose barely pronounceable Latin names include such humdingers as Symphyotrichum oblongifolium and Symphyotrichum novae-angliae. Most gardeners still wisely refer to them simply as asters.
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Other daisy-flowered species hide their lineage under a bushel. It’s only by examining the tightly clustered flowers of the hardy perennial known as achillea (yarrow), for example, that you can appreciate that each one is a perfect daisy in miniature. The same goes for the tiny yellow blooms of goldenrod (Solidago) and the silver-white flowers of the white mugwort properly known as Artemisia lactiflora ‘Elfenbein’. And then there are others – not ornamentals so much as edibles – so surprising that they seem like cuckoos in the nest. Put your hands up if you knew that the humble lettuce is yet another supremely garden-worthy member of this huge plant family, as are chicory, artichoke and salsify. Life, as they say, is full of surprises… And, of course, daisies.
This Week
Now that the scented flowers of lavender are fading, it’s high time to take a garden shears to these sun-loving plants to cut them away, making sure not to cut hard back into old wood.
Cooler nights and the resulting strong swings of temperature can often create problems for plants growing under cover of a glasshouse or polytunnel at this time of year, resulting in an uptick in pests and diseases. Reduce the risk with good ventilation and quick removal of any dead, damaged or diseased plants before the problem gets out of hand.
Dates for your Diary: Sunday September 8th, the Annual ISNA Autumn Plant Fair will take place from 11am-4pm, with a wide variety of stalls by many of the country’s leading small specialist nurseries, see irishspecialistnurseriesassociation.com and fotahouse.com; September 21st-October 6th, Mount Venus Nursery Autumn Sale, with 20 per cent off all plants, Mount Venus, The Walled Garden Tibradden, Mutton Lane, Dublin 16, see mountvenusnursery.com for details; Friday, October 4th-Sunday, October 6th, Kells Bay Gardens – Southern Symposium IX with an impressive line-up of guest speakers that includes UK gardener, writer and broadcaster Adam Frost of BBC Gardeners World, Scott McMahan of Atlanta Botanical Gardens, Jimi Blake of Hunting Brook Gardens in Co Wicklow, Derry Watkins of Special Plants Nursery in England, and Raf Lenaerts, the Belgian gardener and well-known Magnolia expert from Belgium. Pre-booking essential, see kellsbay.ie