It's the floral emblem of Western Australia, has flowers that evoke our best-known native animal and is one of our signature plants – so in the lead-up to Australia Day, it seems only fitting to focus on the Kangaroo Paw.
All strappy leaf, statuesque stem and furry bright flowers, Anigozanthos are experiencing something of a heyday. They do all the things we like to see in our landscapes today – move in the wind, work well in naturalistic drifts, have a graphic sculptural form and flower for ages.
Having flourished in impoverished south-west Western Australian soils for tens of millions of years, Kangaroo Paws are now being tended in more moist, fertile ones further afield. The English cultivate them as annual bedding, Californians grow them across granitic hillsides and the Israelis nurse them in poly tunnels for the cut-flower market. You can see them in gardens everywhere from inner-city Melbourne to the Victorian coast and the central goldfields but horticulturalist and breeder Angus Stewart wants to see them in abundance everywhere from the tropics of Cairns to cool temperate Hobart.
But as Stewart said at a recent conference on Haemodoraceae – the bite-sized family of which Anigozanthos is a member – "roses and camellias have had a couple of thousand years headstart".
"Kangaroo paws are not as garden-friendly... but we are making excellent progress," he said. "The genus has only been in cultivation for a short time, people have been breeding it for even less time ... the breeding is in its infancy."
Breeding Anigozanthos started to take off in the 1960s. Stephen Hopper, professor of biodiversity at the University of Western Australia, says they had been "in the doldrums" before that. Hopper was the keynote speaker at the November conference, the world's first devoted to Haemodoraceae.
While the conference also discussed Conostylis and Wachendorfia and some of the 14 other genera included in the family, Kangaroo Paws were singled out for special attention.
The flower hunters of the 1800s were fascinated by them. Anigozanthos flavidus collected in the Nicolas Baudin expedition of 1800 to 1803 were grown in France, and then England in the early 19th century. But in recent decades Kangaroo Paws have been embraced with a renewed fervour. New ones are being identified and there are currently 12 species and eight sub-species of Anigozanthos, as well as the closely related Black Kangaroo Paw or Macropidia fulginosa. Scientists have identified components in bushfire smoke that best promote seed germination, while there is also much research into the impact of different pollinators, including birds and insects (birds do the best).
There is also increasing experimentation into hybridising Kangaroo Paws to make more robust cultivars for gardens across a broader climatic range. As well as improving disease resistance, the aim is to produce a wider array of colours (most recently purples) across a variety of flowering heights (up to two metres).
Pioneering breeder Keith Oliver told the conference that in the 1960s he realised "that A. flavidus was the one to go for" when hybridising, and this tall and adaptable species is still commonly selected as at least one parent for crossing. While it doesn't have particularly showy blooms (they are typically pale green-yellow), when crossed with other Anigozanthos species, the effects can be amplified. Crossing it with A. rufus, breeders have produced plants with red, burgundy or orange flowers. Partnering it with A. pulcherrimus has turned out plants with yellow, orange and red-and-yellow flowers, while a A. humilis blend has resulted in shorter cultivars suitable for pots. Crossing different forms of A. flavidus alone makes for some particularly vivid colours and tall forms.
The pigment intensity of the flowers, which appear in spring and summer, changes with the weather. Warmer temperatures yield more faded colours. More problematic for gardeners are the fungal diseases that can strike, including leaf rust and ink spot. Speakers at the conference agreed the best way to deal with these was to select resilient cultivars and strictly limit the amount of time the leaves are wet as a result of irrigation. Snails and slugs can also present problems, as can frost, hail and poor drainage.
Taller Kangaroo Paws are the easiest to maintain and respond well to being cut back to ground level, especially when there is dead or blackened foliage. While they grow in infertile soils in the wild, they like to be fed in the garden; most are not sensitive to phosphorous.
En masse, they also like to be slashed and burned. Gingin Cemetery in Western Australia has become a case study in what not to do. In the 1970s, the cemetery was home to 10,000 wild Kangaroo Paws and, when they were in flower, up to 10 tourist buses would stop each day. But, after slashing and burning ceased, and the land was partly bulldozed to make way for a walking track in the 1990s, their numbers plummeted.
We are only now coming to grips with the best ways to cultivate them in our gardens and foster them in the wild. Digby Growns, senior plant breeder at Kings Park in Perth, told the conference the "standard treatment" for germinating Kangaroo Paw seeds at the garden: "They are aged in paper bags at room temperature for a minimum of eight weeks, put in a 100C oven for one to three hours, soaked in smoke water for 24 hours, sowed for two weeks at 15C and then brought into a 25C glasshouse whether they have germinated or not."
Happily, nurseries are saving us all that effort by stocking an ever-growing range of potted paws.