Tree of the moment: Eucalyptus caesia

Strolling through the Royal Botanic Gardens in Melbourne last month and spotted this  beauty with its scarlet flowers and white bark and looking especially striking against the blue sky.

The flowers of Eucalyptus caesia. Photo: Sandra Simpson

An entry on the Gardens website recommends this tree for home gardens and says: There are two distinct growth forms which have been previously described and sold as E. caesia subsp. caesia, which is a small tree, growing from 6-9m tall, and the other is E. caesia subsp. magna (also sold in nurseries as ‘Silver Princess’), which may grow up to 12m tall, with narrow wispy stems and long weeping side branches.

In both forms, the large rich pink or reddish flowers occur in drooping bunches in autumn and winter. The new shoots and leaves start reddish in colour then, like the flower buds and fruit, develop a grey waxy coating which adds a ghostly appearance to this very attractive species. The bark of mature trees is minni-ritchi type, rolling and peeling off in slender ribbons, adding further character to the tree.

 It prefers well drained soils and full sun, and is very drought tolerant once established. The leaves may get fungal leaf spot during damp winters or if there is poor air movement around the plant. The trees can be coppiced to ground level to encourage new stems.

The silvery-white trunk and gumnuts. Photo: Sandra Simpson

I shouted myself a beautiful, large book – Eucalypts, a Celebration by John Wrigley and Murray Fagg (Allen & Unwin, 2012) which says:

“This species is probably the best known of the small ornamental eucalypts in cultivation. In nature it is rare, always associated with granite outcrops in the eastern wheatbelt of Western Australia … The silvery-grey branches are pendulous and often weighed down in late winter and spring by the large pink flowers and urn-shaped gumnuts. A subspecies (subsp. magna), often sold as ‘Silver Princess’, has larger flowers and fruits, with the pendulous branches often touching the ground. Both subspecies thrive in well-drained soil on sunny sites in areas of winter rainfall.”

This eucalyptus is of the mallee type, which means it grows several stems from an underground lignotuber and will grow no higher than 10m. There are areas in Australia where shrubby mallee eucalypts are the dominant form.

The Big Dry

Xeriscaping – or landscapes that need little water – is a trend that’s well-established across the Tasman and is something that Kiwis living in the northern half of the North Island should consider as climate patterns change.

Melbourne has recently come out of a 10-year drought but, experts say, the respite is the anomaly and residents should get used to the idea of water conservation as a way of life.

The city’s renowned Royal Botanic Gardens, rated among the top five in the world, is restoring and expanding upon a water recycling system that was established in 1876 with “Guilfoyle’s volcano”, a reservoir that gravity feeds irrigation systems that run into wetlands and lakes before water is pumped back to the reservoir.

The Victorian folly is now the centrepiece of an “arid garden” that includes cacti, succulents and bromeliads mass planted, some of them to resemble flowing lava down the lower slopes of the volcano.

dry-crassula

A Crassula succulent flowers madly on a scree slope of Guilfoyle’s volcano in the Melbourne Botanic Gardens. Photo: Sandra Simpson

For home gardeners the trick is to select plants that will withstand everything your climate can throw at them – from frosts to drought and from strong winds to a high winter rainfall – and still bring you pleasure.

Group plants together that have similar water requirements and get serious about mulching as this will help the soil retain its moisture.

There’s no point creating a cactus garden if your heart isn’t in it, but there’s no harm in doing some research to extend your plant horizons.

The well-illustrated Succulents by Wanganui plantswoman Yvonne Cave (2002, revised in 2009 published by Godwit) is a good place to start or if you’re in the Tauranga area schedule a visit to El Jakedo Cactus Nursery and Garden in the Welcome Bay Hills (phone 07-544 1178) or Paloma Gardens near Wanganui to see how plants can be used.

dry-euphorbia

Eremophila glabra pictured in the Royal Botanic Gardens, Melbourne. Commonly known as tar bush, the plant is native to Australia. Photo: Sandra Simpson

Award-winning Kiwi landscape designer Xanthe White includes a chapter on dry gardens in her 2012 book The Natural Garden (published by Godwit) and she makes the good point that “a dry garden does not need to resemble a desert”. At the end of the chapter is a series of design considerations that include water storage and distribution and shade, as well as a plant list.

“Closed rooms can become sensual sanctuaries from a harsh environment,” she writes. “Colour, fragrance and water are all carefully embraced as essential elements. Efficiency is paramount, though. Where water is scarce, not a drop should be wasted, nor used but once.”

Hear Xanthe talking about the book (9 minutes, 44 seconds).

Renowned English gardener Beth Chatto has created a gravel garden in harmony with the environment – Beth Chatto’s Gravel Garden was published in 2000 or visit her website for a plant list. Here is a little more about the gravel garden from a knowledgeable visitor.

dry-libertia

The flowers of a Libertia – the plants are more commonly grown for their strappy, golden foliage. Photo: Sandra Simpson

Plenty of New Zealand natives are drought-tolerant – among them cordylines, flax, astelias, corokias, lancewoods, pohutukawa and the native iris (Libertia) – and there is a wide choice of tough Australian and South African natives, including Eremophilia glabra (red flowers or the yellow-flowered Kalbarri Carpet), kangaroo paws (use full-sized Anigozanthos for a longer-lasting plant) ti-trees, Oldenbergia grandis with its outstanding foliage and clivia, which are also shade tolerant. The plants of the coastline of Chile, Peru and Brazil might be worth investigating too.

dry-banksi

The new growth of Banksia speciosa is striking. Photo: Sandra Simpson

The palette is widened by plants from similar Northern Hemisphere climates such as the shores of the Mediterranean, Canary Islands, California (southern California has a dry climate, while northern California is a bit wetter) and Mexico.

  • Further reading: Colorado State University’s useful website on xeriscaping.

Some of this article was first published in the Bay of Plenty Times and appears here with permission.