We find out how you can take an active role in protecting the future of the Convent’s unique heritage gardens with Head Gardener Simon Taylor. We speak to Simon about the importance of increasing our rainwater catchment, future proofing against climate change, and utilising the knowledge of our dedicated volunteers.
With more extreme weather events happening more often, how can people best protect their gardens from such intense seasonal variations?
Acclimatizing your garden to extreme weather variations is a process that we have not had to be concerned with in living memory, so by its very nature it is experimental. This is often a gardener’s lot! Increasingly we design gardens to be supplemented or totally reliant on the harvesting of stormwater. Calculating roof catchment area informs the garden area that can benefit from it, at a 1:1 ratio. Any garden area beyond that ratio we design to be extremely drought resistant once established.
Is it a challenge to find a variety of plants that can survive the peak summer heat as well as Melbourne’s cold, wet winters?
Currently no, in part due to Melbourne’s rich horticultural heritage and preservation of historically significant parks and public / private gardens. As these seasons change however, we need to adapt to varying climatic conditions and the opportunities and constraints they entail.
Even with climate change, native species can find themselves at risk. How else can people future proof their gardens against increased heat?
Forecasts suggest current indigenous plant species from the ‘Melbourne Climatic Zone’ may well suffer with predicted climate change. Forecasts also suggest a more northern (hotter & drier) climate will venture southward to Victoria. The solution for gardeners is to experimentally introduce native species from a neighbouring northern climatic zone. This becomes increasingly imperative for long lasting tree species that have the potential to live for dozens or even hundreds of years. It is useful to remember that Australia was once fully covered in rainforest, so these fluctuations have always existed. What is unprecedented is the speed with which climate change is currently occurring and we have to be prepared to pro-actively face that challenge head on.
How many drought resistant plants do you hope to plant in 2018?
Through seed, thousands; from direct in-situ cuttings, hundreds or even thousands; by direct planting, dozens.
Does changing the make-up of the garden that way affect the heritage values or qualities of its design?
With foresight and appropriate planning these changes will enhance the gardens. Most of what we witness today is the work of the nuns in the latter half of their 100-year residency. Prior to a 1905 redesign, the garden of today is unrecognisable, so ebb and flow has always been apparent in the grounds appearance, function and botanical collections.
Through our Keep it Green: The Water Story appeal, we’re hoping to double the amount of rainwater we capture each year, to four million litres, by installing more piping and water tanks. What’s the single biggest impact this investment will have on the garden?
For the last eighteen months, the Contemplative Garden has been fully irrigated from ‘holy water’ (stormwater) without the addition of any mains water supply at all. This significant feat has effectively ‘doubled’ the gardens rainfall and the benefits are there for all to see (sometimes a green thumb can help to enhance the eyesight).
We are currently only harvesting a fraction of the Convent’s stormwater supply. Any increase harvesting from here will allow us to extend attention into neglected corners of the property and will also help drought proof the gardens when reduced rainfall does come.
Our crude rule of (green) thumb is – one square metre of roof can support one square metre of garden, so the more we can harvest, the more we can grow.
What current plants or trees in the heritage garden will benefit most from additional watering?
The property as an entire ecosystem will benefit from ‘increased rainfall’. The last three spring / summer seasons have been kind to gardeners in Melbourne but the previous drought damaged and in some cases devastated many gardens. There are a few lessons we learnt from those drought conditions. Firstly, make all attempts to improve the condition and depth of your topsoil. The reasons for this are obvious to most, but one factor often overlooked is that good topsoil has a water holding capacity of 40 per cent. The deeper the topsoil, the more water can be stored where it’s most needed. Secondly, pulse watering is far more effective than a single irrigation. If you are currently irrigating a garden bed or lawn for say 20 minutes, consider adjusting the regime to three seven-minute watering sessions with 15-minute intervals between each. This will let the water penetrate more effectively than a single irrigation. At the Convent we are loading up not only the sponge that is our topsoil but the shallow underlying aquifers also. This sponge loading dramatically helps all the plants.
To make this a reality, we’re asking people to donate, but there’s other ways people can help our garden thrive. We have a dedicated team of volunteers who get their hands dirty every week. How can people take part and what can new volunteers look forward to doing in the gardens?
A well-trained and observant gardener needs to witness each season at least twice to glimpse a property’s attributes. One of the most rewarding traits of the Convent is that we have numerous volunteers who have witnessed each season dozens of times. This is a priceless resource that offers insights into our unique property and gardening techniques in general. The gardens would not survive without our volunteers and our plans are to expand the gardens, so their input – and that of any new volunteer – is as essential as ever. Our whole community is indebted to them.