Steffie Shields recommends some easy-to-grow plants that thrive in heatwaves.
As ever, the good old British weather cannot make up its mind and is keeping us guessing again this summer.
Temperatures rise and fall with no apparent pattern, rhyme or reason – one Sunday a scorching mini heatwave, the next day overcast with thermostat numbers diving low enough for many of us to contemplate putting the heating on in July!
If humans cannot manage this barometric rollercoaster, then how on earth can we expect our garden plants to thrive?
Quite possibly a result of last summer’s extreme heat, I now mourn a venerable, faithful friend. A short, modern climbing rose, Joseph’s Coat, inherited from the previous owners, on the west-facing wall of the house gave up the ghost last winter.
Welcoming all comers for the past 24 years, I loved its gentle fragrance and how no two blooms were the same. It bore gorgeous semi-double flowers in loose clusters of soft petals, a cheerful mix of rich oranges, yellows and, on occasion, a stunning red to deep scarlet that made this photographer’s heart sing.
An ornamental mountain ash tree, Sorbus aucuparia, planted directly opposite, stands guardian to the gate as the more traditional sign of welcome to visitors coming up the drive. Come August, large ripening clusters of bright red berries blowing in the prevailing west wind will now be the sole attraction in the sunshine.
Thriving in a heatwave
So, what else will thrive in our gardens this month if a prolonged heatwave finally arrives? Echinacea, commonly called coneflower plants, are easy to grow with daisy-like flowers attractive to bees and butterflies. These bold, tough perennials look particularly good with grasses in prairie-style late summer borders.
Smaller bright orange daisies, formally known as Calendulas, are one of the oldest cultivated plants in the world. Unfussy plants, they flourish in ordinary soil, even poor, dry soil and, as with echinacea, flower best in full sun, along with Crocosmia ‘Lucifer’.
This easily recognisable, striking plant, heralded by the celebrated late plantsman Christopher Lloyd at Great Dixter in Kent, grows in great swathes in the border, with upright narrow, sword-shaped foliage, interspersed with arching sprays of fiery red tubular flowers opening in turn to great tropical ‘hot border’ effect.
Rudbeckia remains a firm family favourite, ever since my daughter, Gabrielle, aged eight, impressed the ticket man at The Savill Garden with her plant knowledge. Diving under the turnstile and skipping away towards the nearest vibrant border, she called back to me: “Ooh Mummy, look! They grow Rudbeckia ‘Marmalade’!” How easy is it to remember those plants with amusing names, many recommended by TV gardening guru Geoff Hamilton on Gardeners’ World?
This year marks the 40th anniversary of Geoff’s wonderful creation Barnsdale Gardens, a stone’s throw from Rutland Waters. I returned recently to discover its many diverse areas all still beautifully maintained by his son Nick Hamilton, and paid due respect to his father’s memory and legacy.
Many of my generation owe Geoff so much, for his passionate encouragement, wonderful insights, and inexpensive, innovative ideas and inspiration. He made all manner of gardening seem so possible and well worth having a go. Treat yourself and your family to a visit.
Loved by bees
Last year, Gabrielle and granddaughter Emily successfully raided our nearest garden centre, on a mission to cheer me up after an operation. Seeing their smiling faces and reading the amusing names on the labels, I knew why they could not resist bringing Rudbeckia ‘Laughing SmileyZ’ and Rudbeckia hirta ‘Lemon SmileyZ’ home.
A new type of ‘black-eyed Susan’, the former is hugely attractive to wildlife, adding rich browns, oranges and yellows to our various patio pots. The latter is equally uplifting, if more compact bearing lemon-edged, yellow daisies with green button centres, also much-loved by bees.
My husband and I, plus an army of pollinating insects, enjoyed massive numbers of flowers with smiley faces through to the end of October. Having later transferred them into a long border, I unfortunately neglected to either mulch or protect them from some severe frost. Sadly, although supposedly hardy, and with an RHS Award of Garden Merit, neither perennial saw the winter through.
A recent report about last month’s Hampton Court Palace Garden Festival highlighted a Gold Medal-winning garden by designer Zoe Claymore, sponsored by the Wildlife Trusts. ‘The Renters’ Retreat’ aimed to empower and inspire tenants, landlords and homeowners to improve outside spaces for wildlife.
It showed health and wellbeing benefits of making outside spaces greener – even in unlikely urban settings.
Its clever flat-pack design could be taken down and re-built easily, using a German idea – a hügelkultur or mound culture – a permaculture system to create moisture holding beds that successfully reduce watering needs while also supporting wildlife. It built up log planters with layers of plant matter and compost which retain moisture and decay over time, creating a modular planting bed that can be dismantled and moved around. This layered approach improves diversity and quality of soil, retaining moisture and nutrients in the earth, helping plants to grow.
During hot summer months, it is sensible to water slowly by sprinkling plants down at their roots, giving them a good, long drink every two or three days. Remember, if temperatures become extreme, water every day, either first thing in the morning or late in the day towards dusk – never in the scorching heat of the day.
Over at least two decades, I have managed to both keep and grow fresh cuttings of two garden gems: Penstemon ‘Garnet’, a good ‘doer’ with elegant, wine-red foxglove-like flowers for the front of a south or west-facing border; and the larger, arresting Penstemon ‘Vesuvius’, bearing mid-purple flared, tubular flowers with an attractive white throat streaked with purple.
Both these bushy, semi-evergreen perennials produce flowers effortlessly all summer. If you tidy them by a ‘Chelsea trim’ come May, reducing their upright stems by half, they will shoot up afresh, rewarding you with flowers until the first frosts.
Every August, I suffer a frisson of plant envy on passing my neighbour’s fabulous myrtle shrub, laden with large creamy, white flowers offset by small, aromatic, ovate, almost leathery leaves.
The profuse bowl-shaped blossoms are followed by interesting purplish black, apparently edible, berries in full sunshine facing south and sheltered against the fence.
Having witnessed it flourishing in hotter summer temperatures, I recommend this evergreen, summer-flowering Mediterranean shrub, Myrtus communis, with its RHS Award of Garden Merit, one of the most famous plants in history thanks to its amazing health benefits.
Perk up borders or pots with easy-to-grow red and yellow lilies. Last August, a new introduction, Lilium ‘Purple Dream’ made a talking point, and a fine contrast to many flowers the colour of sunshine! Similarly, the delicate-looking Thalictrum delavayi ‘Hewitt’s Double’, an erect herbaceous perennial with attractively divided maiden-hair fern-like leaves, made a pleasing partnership with a perennial golden daisy sunflower, Helianthus tuberosus, or Jerusalem artichoke.
Tall, airy panicles of long-lasting, tiny rosette-like, double lilac-purple flowers with the taller, pretty sunflowers en masse made a useful, windbreak in full sun – more smiles all round!