Australian plants offer great choices for Southern California and other mild-climate gardens
Most Australian plants have evolved on lean soils with a lot of sun and periods of drought. If you are going to be successful growing them, you will need to give them conditions that mimic the ones they developed in. These plants, on the whole, prefer a slightly acid soil and most of them are shy of phosphorus so avoid feeding plant foods with phosphorus. Some will take frost, but most will not survive hard frosts so if you want to grow them in the higher elevations where winters get snowy and icy, you will have to do it in a sun room, greenhouse or a pot so you can bring them inside during the winter. In the warmer parts of areas like Southern California you will have a less limited selection.
Eucalyptus offers a broad selection of graceful and interesting trees. Most are attractive, drought-tolerant, evergreen trees, but many are prone to grow long branches that can break in our winds. A lot of Eucalyptus trees are high in volitile oils so they can be flammable in areas exposed to wildfires. Still, now that the devastation caused by the invading lerp insect has become less destructive to this group of trees, you might want to plant the red gum tree or the cider gum tree (Eucalyptus gunnii 'Silverdrop') for showy choices of Eucalyptus tough enough for almost any micro-climate in Southern California. Eucalyptus trees can grow from small sized specimens to very tall. Most have fascinating bark that can come in interesting colors and textures. And some of these Australian trees have very showy flowers.
The familiar bottlebrush is an Australian plant that has a smaller, more appealing variety you can use in your garden. Callistemon 'Little John' grows to only 4 - 6' tall and will have the same showy, red flowers without the lanky, overgrown look common to its larger cousins.
A delicate vine is the Hardenbergia. This plant will drape over walls, trellises and fences. It is evergreen with narrow leaves and thin, twining stems so it has a delicate look to it. In late winter it covers itself with panicles of hanging purple (or pink) flowers that dangle like little grape clusters.
Check into the family of Acacias or Cassias for some very showy yellow-flowered shrubs and trees. Acacia or 'wattle' is a big family of ground-cover plants to small trees. Most bloom with big clusters of fuzzy yellow flowers. Often Acacias have a wonderful perfume. Try the decorative Knife-leaf Acacia (Acacia cultriformis) for a graceful, fanning large shrub or small tree with an artistic flair. Or cover your hillsides with the low-growing ground-cover, Acacia redolens 'Low Boy'.
There are spectacular flowers offered by the Grevillea family. This is another large family that offers low-growing plants to tall trees. The blooms have that Australian hook-like brush appearance, mostly in a cone shape, and come in a whole range of exciting colors. Some also have decorative leaves.
The Hakea family tends to be made up of shrubs and small trees. Blooms can be very showy and come in a lot of different colors. Most Hakeas have brittle or scratchy foliage and some can look a lot like small pine trees when out of bloom.
The Anigozanthus, or Kangaroo Paws, are becoming quite popular in gardens because they are so unusual-looking. They do need good drainage and some varieties will need protection from cold. There are small varieties to 1' tall and some that grow to 5' in height. They grow in clumps of strap-like foliage and throw up curious flower spikes with fuzzy paw-like flowers. Varieties come in reds, oranges, yellows, pinks and greens â some even offer a unique bright blue-green. These make good cut flowers as well as powerful accents in the garden.
These suggestions comprise only a small selection of the many amazing-looking Australian flowers now available for the Southern California garden or other warm climate areas: there are many more. You may have to search a bit for your favorites, but with drought-tolerant gardening gaining in popularity, garden centers are offering more and more interesting Australian plants for sale. Use these plants in the landscape to add texture and beauty. They will illicit curiosity and envy from all your garden visitors. And most are low maintenance when it comes to care.