A brightly coloured garden will await you in the warmer months with these old-fashioned floral gems
old-fashioned dahlias and tuberous begonias are considered the ultimate in garishness by some people. In fact, both can be used effectively in highly contemporary settings.
Whatever your style preference, dahlias and begonias should be top of your list to plant now for stunning, long-lasting summer colour. Dahlias From diminutive ‘Baby Dahls’ and ‘Little Dahlings’, both bred specifically for container culture, to massive cactus-flowered dahlias, there’s a variety to suit every taste.
Some keen (aka eccentric) gardeners grow dahlias for “exhibition blooms”. But as well-known and revered dahlia breeder Dr Keith Hammett concludes after years of producing exhibition dahlias, “I came to the realisation that the plants I was breeding looked like a bunch of severed heads on sticks!”
Nevertheless, large-flowered dahlias still possess an irresistible charm. Being among a bed of tall, gaudy coloured, massive dahlia flowers is like being transported to Alice’s Wonderland. I do love them – in other peoples’ gardens. But I prefer growing the easy-to-maintain and compact varieties which Dr Hammett now concentrates on breeding.
His New Age dahlias, including ‘Kapow’, ‘Knockout’, ‘Scarlet Fern’ and ‘Best Bett’, have demure single flowers over deeply divided, dark mahogany foliage. They’re great for mass planting or creating colour and associate well with many native plants, particularly grasses and low-growing coprosmas.
Dahlias for sun
Position in full sun and shelter.
Provide water-retentive but well-drained soil.
Fork plenty of compost and sheep pellets through soil before planting.
Plant tubers 10-15cm deep (20cm deep for large robust varieties).
Stake tall varieties at planting time by pushing three strong stakes into soil around tuber, on an angle to form an inverted cone.
oulch with fine bark or compost to conserve soil moisture over summer.
Scatter slug and snail bait in a circle around tuber to help protect the emerging shoots.
Fertilise weekly once shoots emerge with liquid fertiliser (seaweed, fish, or blood and bone).
Water regularly to keep dahlias (which are 95% water) turgid.
Deadhead spent blooms frequently to promote new buds and keep plants tidy.
In autumn, once foliage dies down, either leave tubers in ground (if soil is really well drained) or dig up, dry out and store in sawdust or coarse sand in the garden shed, ready for planting next spring.
Tip! To promote further flowering, remove pointed buds (which are seed pods) and leave round buds (which are flower buds).
**Tuberous begonias
**once considered a tender houseplant, these days you’re more likely to see Tuberous Begonias mass planted in a riot of brilliant colour through subtropical undergrowth, or adding colour to foliage plants in a large bowl on a deck.
Although tropical looking and well-suited to the subtropical theme, Tuberous Begonias are actually temperate climate plants just like dahlias. Tubers will rot in cold, wet conditions though, so they must be stored dry over winter. Those labelled “Non stop” are ideal for mass planting in garden areas.
They are compact plants, 20-30cm high, which produce masses of flower and do not require staking. Large-flowered types require a little more TLC. Staking prevents heavy blooms snapping fragile stems and shelter from rain is best to protect their exquisite blooms. Slug bait is essential for both types!
Begonias for shade
Plant tubers into pots filled with coarse potting mix.
Add slow-release fertiliser pellets.
Place pots in a sheltered place.
once shoots are well established, position pots in sheltered, semi-shaded spots around garden.
Provide good light, but not direct.
Scatter slug bait around pots.
Fertilise weekly with liquid fertiliser (seaweed, fish or blood and bone).
Watch for caterpillars and powdery mildew and treat accordingly.
Deadhead spent blooms frequently to promote new buds and keep plant tidy.
**oatch watering to the growth cycle
**Shoots just emerging (Sept-oct): light watering every time mix is dry. Active growth (oct-April): good soaking when potting mix has almost dried out. Dormant (oay-August): remove pots from garden and allow to dry out.
Tip! For larger double flowers, remove the two side buds on each flower stem, allowing only the larger central bud to form.
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