Thursday, 8 August 2013

It's not called "Botany" Bay for nothing.

  Hawkesbury Sandstone is the surface bedrock of the greater Sydney basin. It covers an area of approximately 17,100 square kilometres . Two hundred million years ago, mountain ranges in Antarctica were eroded and produced vast quantities of sand. This was carried by a huge river system across southern Australia from Antarctica (then part of Gondwanaland). These sands were deposited into the Sydney basin where they were consolidated into sandstone up to 50 metres thick . This sandstone is the basis of the nutrient-poor soils found in Sydney which developed over millenia and 'came to nurture a spectacularly diverse range of plants. “It is a singular fact that in Australia the most brilliant flowers are found on the most worthless country” wrote A.G. Hamilton in 1930. 

 The fact that the impoverished soils were not suitable for agriculture means that large areas, around the city, have been conserved into modern times.  But now, urban sprawl is sadly taking its toll. Foreign invasive weeds are thriving on all the nitrates and phosphorus washed into the bushland from our roads and gardens but the highly evolved natives, which can’t survive high nutrient levels, are being decimated. The gardening “experts” meanwhile encourage us to fertilize and spray our back yards at every given opportunity which compounds the situation. They’ll also try and seduce you into purchasing commercially created, hybrid “natives” which are both expensive and unauthentic (they might even impact negatively on the gene pools of genuine endemic plants.

 It’s not too late to grow some Hawkesbury Sandstone “originals” though. Firstly acquire them from a reputable indigenous plant nursery or from your local Council.  They are much cheaper, require no fertilizers or pesticides and are perfectly adapted to local soil and climatic conditions.  Whack them in your, non macro-nutrient enhanced, patch of dirt. Then, sit back, enjoy and feel a closer connection to the natural world! Here are some wonderful examples of native plants currently in bloom on Sydney’s Northern Beaches  which would look glorious in your garden (if you live around here).

Epacris Longiflora (Native Fuschia)
Grevillea Speciosa (Red Spider Flower)
Hakea Sericea (Bushy Needlebush)
Hibbertia Scandens (Golden Guinea Flower)
Acacia Longifolia (Sydney Golden Wattle)
Woollsia Pungens (Snow Wreath)
Dendrobium Speciosum (Rock Lily, Rock Orchid)

This book by Les Robinson is a fantastic resource and contains a wealth of valuable info.