Why are Australian summer gardens so disappointing?

The English Garden, which sadly mostly Australian gardeners still regard as the model to be aspired to, is only possible in a climate that is far more benign and consistent than the extreme diversity of climates we have in Australia.

When you think about it, it's a preposterous idea to have such a garden here. Only in Tasmania (and not even Canberra) are the number of days with temperatures over 30°C fewer than 7 a year.

If you look at each of our major cities, Darwin has 360 days a year over 30°C, Perth 60 days, Adelaide 45-60 days, Melbourne 30-45 days, Sydney 30-60 days and Brisbane 45-90 days. In fact, in geographic area 95% of Australia is unsuitable for the English style of garden. By population it is worse in that 98% of our population live in a climate far too hot for this garden style.

With a climate as diverse as Australia's our garden styles will vary and our palette of plants vary too. Across our huge continent there are four general styles:

• Tropics: Lush, green, shady gardens, in areas with summer rainfall (Heat Zone 5-14).
• Desert: Arid foliage native gardens (Heat Zone 8-12).
• English: Tasmanian cottage English style (Heat Zone 1-3).
• Modern Suburban: Plants that thrive with up to 60 days of 30°C (Heat zone 4-6).

The modern English Garden is anything but filled with native plants with over 70% of plants in English gardens are imported.

Just as Australia was establishing gardens in the 1850s, English plant hunters realised the poverty of their natural plant inheritance and began a love affair with imported plants, bringing back Rhododendrons from the Himalayas, Magnolias and Roses from China, Blue Poppies from Tibet and Hydrangeas from Japan.
These plants are now regarded as essential elements of an "English Garden" and subsequently they were planted in colonial gardens too.

Japanese gardeners also imported plants into their gardens, but they didn't share the English dissatisfaction with local plants as their native plant selections were adapted to their garden tradition 600 years previously.

Whilst the culturally sophisticated Japanese have long valued their natives, Australia's revival of interest in native plants didn't occur until after World War II when Eucalypts, Callistemons and Melaleucas were planted extensively as native garden trees, particularly (and unsuccessfully) as street trees.

Whilst they are perfectly adapted to our arid climate with leaves that hang down (Eucalypts) or needle leaves (Melaleucas and Callistemons) they provide poor shade on oppressively hot days.

Because most Australian shrubs come from the arid zones (with 70% of Australia a desert) the garden impact of planting the bush in our backyards brings a dry look to our summer gardens which is the opposite of the cool refreshing textures most gardeners seek during those hot, nasty summer days.

Deciduous trees from China, USA and Europe were planted because they provided good shade and many had excellent autumn colour, but the slow growers or those unsuited to hot dry summers, disappeared. Australia's rainforest had yet to provide the lush, green, drought tolerant foliage in gardens other than Lilly Pillys and the White Cedar (Melia azedarach var. australasica).

Whilst we were adapting exotic trees and shrubs to our gardens, overseas plant breeders began marketing impulse potted colour where fast growing annuals with enlarged flowers and dwarfed heights replaced the familiar herbaceous, less showy but more harmonious perennials and bulbs like Dahlias that filled our gardens. This trend focused so heavily on spring flowering plants that the summer flower garden almost disappeared.

As an antidote to this excessive spring focus, drought tolerant perennial selections are a feature at Heronswood, St Erth, Cloudehill and at our Royal Botanic Gardens in Victoria, creating great beauty similar to the finest flower gardens in England, Europe and the US.