IN FOCUS: THE BLUE MOUNTAINS BOTANIC GARDEN Red Wattlebird feeding on nectar produced by the magnificent Puya alpestris ssp. zoellneri (family Bromeliaceae)
SENSE & SENSIBILITIES SUMMER AT THE BLUE MOUNTAINS BOTANIC GARDEN IS AN ENTICING TREAT FOR THE SENSES. SENIOR HORTICULTURIST MARION WHITEHEAD TAKES AN IMMERSIVE TOUR.
F
rom the structure of deciduous trees revealing themselves in winter to bright bulbs poking their heads above ground in spring, different seasons offer very different ways to immerse yourself in the garden. Summer is no exception, especially at the Blue Mountains Botanic Garden, where visitors are surrounded by all manner of sensory experiences.
SMELL
There is nothing like the smell of rain falling on a summer day. In 1964 two Australian scientists working at the CSIRO published the first scientific
22 THE GARDENS SUMMER 2021–2022
description of that odour and gave it a name: “petrichor” (from the Greek “petra” for stone and “ichor”, the blood of the gods). Petrichor is caused by a soil-dwelling bacterium creating a chemical compound called geosim as it breaks down organic matter in the soil. The smell has been shown to improve our mood, with our noses able to detect the scent of geosim in the air even when diluted to parts per trillion.
SIGHT
In the cool, dark Gondwanan Garden which many visitors retreat to in the heat of summer, the ferns appear to
glow in the early summer afternoons. This is due to what is known as the Purkinje Shift – an adaptation like night vision that means in lower light conditions our eyes become more sensitive to the blue end of the colour spectrum, making green colours appear illuminated. The effect can only be experienced through your eyes and not the lens of a camera, making it a great opportunity to take a breath and enjoy the moment.
SOUND
Thanks to its volcanic soil, Mount Tomah has some towering trees, particularly the
