As we come to the top of spring, lookup from the footpath or on the park, and it’s possible you’ll spot the fiery flowers of the silky oak, Grevillea robusta.
It’s possible you’ll already be acquainted with grevilleas – maybe you’ve gotten low- rising floor cowl and shrub species in your backyard.
Some individuals love the sensible crimson, yellow, orange or white flowers of grevilleas. They’re additionally nesting and roosting havens for small native birds, and so individuals might plant them to draw wildlife.
Of all of the grevillias, the silky oak is the one which catches my eye. It’s the biggest and tallest of the species, reaching as much as 30 metres. They’re now blooming alongside the east coast and in some inland locations – like enormous orange mild bulbs dominating the skyline.
Robust like oak
Grevilleas have an ancestry older than dinosaurs. They originated on the super-continent Gondwana, and are intently associated to banksias, waratahs and proteas.
Right this moment, the 360 species of grevilleas happen in Indonesia and Australia and are a various group. Their vibrant, distinctive flowers lack petals and as a substitute encompass an extended tube referred to as a “calyx”, which splits into 4 “lobes”.
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Like most different grevillea, silky oak possesses proteoid or cluster roots, that are dense and advantageous. These roots enormously improve the absorbing floor space and permit crops to thrive in nutrient-deprived soils.
The phrase “robusta” refers to the truth that the timber is powerful like actual oak. The freshly cut up wooden has a silky texture, and a sample and lightweight color resembling English oak – therefore the widespread title “silky oak”.
Be careful for the cyanide
Grevilleas actually drip nectar, a lot to the delight of native birds and bees. Aboriginal individuals loved the candy nectar straight from the plant or blended with water — the unique lolly water.
However it’s a must to know which species to style as some, together with the silky oak, comprise hydrogen cyanide that would make you unwell.
Like different grevilleas the silky oak additionally comprises tridecyl resorcinol, which causes an allergic response resulting in contact dermatitis. The chemical is just like the toxicodendron in poison ivy.
So when working with silky oaks, you’d be sensible to put on gloves, a face masks, protecting eye put on (or face protect) and lengthy sleeved clothes. Washing palms and showering on the finish of the day can be really helpful.
A prized timber
Silky oak timber was broadly utilized in colonial instances. Then it was marketed as “lacewood”, and that title persists right this moment amongst some who use it.
Silky oak veneer was used broadly in colonial desk tops and different furnishings. Through the years, silky oak has additionally been used to make window frames as a result of it’s proof against wooden rot.
Abroad, silky oak timber continues to be broadly grown, in timber plantations and as windbreaks.
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However it’s not broadly obtainable in Australia, on account of low market demand – the allergens and cyanide it comprises means individuals are usually reluctant to work with it. Nevertheless silky oak continues to be extremely prized by those that make guitars, and wooden turners who make bowls and cupboards.
Within the backyard
Though an evergreen tree, some specimens are nearly semi-deciduous, dropping most of their foliage simply previous to flowering.
Some specimens of silky oak is usually a bit scraggly of their cover type. They will profit enormously from a little bit of formative pruning when they’re younger, and maybe some structural pruning from a great arborist as they become older. Just a little consideration on the proper time can be amply rewarded with a protected and nice trying tree that may reside for 150 years or extra.
Silky oak is drought-tolerant. In dry instances they usually flower a bit later than their regular October blooming, offering an enormous splash of color in in any other case drab and tough years.
The timber will be susceptible to frost when younger, however develop effectively as soon as taller. This makes the silky oak a possible winner as local weather change brings hotter, drier climate.
Silky oaks have been declared an environmental weed in elements of New South Wales and Victoria the place it grows exterior its native distribution vary. They’re additionally thought-about an invasive or invader plant in Hawaii and South Africa. Nevertheless Grevillea robusta is declining in its pure rainforest/moist forest habitat.
In some cities in China, silky oaks have been planted alongside roadsides with nice success. The tree has additionally gained the Royal Horticultural Society’s Award of Backyard Benefit for its efficiency in rising beneath United Kingdom circumstances. That simply exhibits you the way one individual’s weed is one other’s treasure.
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