Urban Gardens – Creating Corridors of Habitat¦Serventy Memorial Lecture with Sabrina Hahn

The Serventy Memorial Lecture is held every year in honour of the contribution made by the Serventy family to Natural History in Australia and to our Club. The lecture raises funds to encourage young people to study natural history. Before the talk, our new president, Shashi Sharma, talked about the significance of our Club and his hopes for a major celebration of the Club on its hundredth anniversary, coming up in 2024. Mandy Bamford then outlined the work of the Serventy family, the foundation of the Club by Dom Serventy in 1924, and some of the achievements of our Club. Then our two Club patrons, Lyn Beazley and Kerry Sanderson took to the stage. First, Lyn Beazley welcomed Kerry Sanderson as our new co-patron, and then Kerry Sanderson introduced the speaker.

sabrina hahn

Sabrina Hahn needs no introduction to most people in WA, being a master gardener, horticulturalist, award winning radio presenter, podcaster and writer. She has a scientific background, has spent 30 years with the ABC and written three books, has conducted garden tours in Europe and has helped Aboriginal people in remote communities create edible gardens. Moreover, she has a great (and irreverent!) sense of humour, which enlivened her talk. Sabrina told us how, as a child in NSW, she and her five “uncontrollable” siblings were often banished from the house, and so they formed what she calls their own “naturalists’ club” exploring the bush and getting to know it (being naughty has its rewards!). Arriving in WA, she was impressed by the exceptional beauty of the local flora and wanted passionately to encourage people to grow native flowers. Her first attempts were unsuccessful, but she started to “sneak” native plants into people’s gardens!

Flora in the SW of our state is special because poor soils (e.g. hydrophobic and low in phosphorus) and long, dry summers have caused plants to develop special coping mechanisms. For example, plants have “learned” to take up small amounts of phosphorus, leaving some for surrounding plants. These adaptations, together with eons of geological stability, have resulted in the development of exceptionally high biodiversity. However, we are on the brink of losing this unique ecosystem, says Sabrina. We have fragmented the habitat. We have cleared vast areas of land, caused disastrous fires, introduced Phytophtera and invasive plants, created urban heat islands and hard surfaces, altered the hydrology by paving and draining, and what she calls “landscraping”, which is how modern housing estates are usually developed – leaving no trees and often no soil. Also, Climate Change has increased the incidence of droughts.

Sabrina laments that a great many people don’t care that we are losing this unique heritage. They don’t care because they are not familiar with the bush and have no understanding of the complexity of the natural world. For that reason, she says, we need to take children into nature. Schools and groups like the Naturalists’ Club can play a part. We all need to learn to observe carefully, let our eye attune to the complexity of the natural world and learn how it all connects. Then we will understand the problem and will want to preserve nature. Sabrina believes that everyone can have a positive role in protecting what we have and giving something back to the natural environment. That is the challenge.

As gardeners, we can help to make a bridge or corridor for wildlife by creating or preserving plant communities in our own back yards and in the neighbourhood. We need to be aware of the relationship that plants have with birds, insects, spiders, fungi, soil bacteria and other organisms. We need to create diversity in our gardens. We need to make sure that there are sources of pollen and nectar all year round for the birds and insects. We need water high and low in the garden for the wildlife. We need trees for the larger birds to roost, feed and nest in. We need a shrub layer (prickly perhaps) for the smaller birds to do the same and find protection. And we need ground covers. We need to develop a good knowledge of plants and think in terms of creating habitat and “inviting species in”.

Sabrina is not a purist about native plants, but it is the natives that the wildlife has adapted to. She is aware of summer dormancy in some plants and does not over-water them during this time. She uses no pesticides at all – not even “organic” ones. She does not use rat baits because she knows that the poison could end up in her local Boobook Owls. She keeps observing in her garden – things eating other things – and allows the system to develop. By doing these things, Sabrina says, we can be an intelligent species that recreates nature. We have the capacity to be caretakers of the planet.

Mike Gregson