Summer shade in our hot, glary, Australian climate is a must. The garden offers a cool retreat and an additional outdoor living area. With the highest incidence of skin cancer in the world, Australians are finally realizing that being out in the sun is not the healthy lifestyle it was once thought to be. We need shade, not only when we go to the beach, but when we garden, play and swim at home. The trees we select for our gardens are very important.
Choosing native shade trees has the advantage of increasing the likelihood of obtaining trees that are appropriate to the conditions and surroundings of your block. Remember, however, that just because a tree is a native does not mean that it will thrive anywhere in Australia! This is a huge country, spanning a wide range of climatic zones. Choosing a tree that is indigenous to your area, providing it meets other criteria, is a good idea and it may also attract local birds and other fauna to your garden.
In you live in southern Australia where it is colder and the sun does not rise high in the sky in winter, it is wise to consider deciduous trees for the northern and north-eastern sides of your block. These will allow the winter sun into the garden and house and help reduce heating bills.
There are not many deciduous native trees available for the garden. The prettiest and most useful is the White Cedar Melia azedarach var. australasica which has pretty bipinnate foliage which turns yellow in autumn. It bears masses of lavender, scented flowers in spring followed by decorative yellow berries that last after the leaves have fallen. It is very drought tolerant, but unfortunately, highly poisonous. Basically, if you want deciduous trees, they will most probably have to be exotics.
An alternative to deciduous trees is to use tall evergreen trees with slim trunks. The low level of the sun in winter means that sunlight may enter the house under the canopy, the trunk creating very little shade. In summer when the sun is overhead the foliage provides welcome shade. However be very wary of planting tall trees close to the house as the roots may cause structural damage.
There are many native evergreens from which to choose. You may find some of these are suitable for your area:
Densely canopied shade trees:
Hymenosporum flavum – Native Frangipani – 10m – beautifully perfumed cream flowers aging to yellow in spring.
Lophostemon confertus – Brush Box – 10-15m – white flowers in late spring. (This tree may grow much taller in the sub-tropics & tropics.)
Melaleuca linariifolia – Snow in Summer – 6m – creamy papery bark – masses of white, scented flowers in summer.
Melaleuca stypheloides – Prickly Leafed Paperbark – 8-15m – white flowers in late spring.
Buckinghamia celsissima – Ivory Curl Tree – 6-10m – glossy leaves – masses of fragrant cream flower spikes in late summer.
Waterhousea floribunda – Weeping Lily Pilly – 15-20m – elegant large tree – creamy berries – suitable for semi-shade.
Corymbia ficifolia – W.A. Flowering Gum – 6-8m – often spectacularly colorful flowers in summer, followed by large decorative gum nuts.
Lighter canopied shade trees:
Eucalyptus leucoxylon subsp. megalocarpa – Yellow Gum – 10-15m – pink, red or white flowers in winter.
Eucalyptus pulchella – White Peppermint – 8-12m – white flowers in late summer.
Eucalyptus nicholii – Narrow-leafed Peppermint – 10-15m – masses of small white flowers in autumn.
Eucalyptus polyanthemos – Red Box – 10-15m – keeps pretty blue/green juvenile foliage for a long time – white spring/summer flowers.
Agonis flexuosa – Willow Myrtle – 10m – weeping aromatic foliage – white flowers in spring
Acacia maidenii – Maiden’s Wattle – 12-18m – long-lived – pale lemon flowers in winter.