The generous verge garden

Verge gardens are the next frontier for creative suburban gardeners. Some councils in Australia are making it easy for people to grow on the nature strip while others have residents guerrilla gardening on the verge.

There are many reasons to love verge gardens. Food production is brought close to home, people bump into each other in communal street spaces, plants help to cool the city in summer and the greenery makes walking home that little bit more pleasing to the eye.

The City of Sydney has cut the red tape for people wanting to garden in the streets. With a motto of ‘green, global and connected’, it’s a no brainer for the council to help street gardens spring up. It has produced a series of guidelines to help people get started and site their verge gardens so the footpath remains accessible for all and the neighbours are happy. A Dial Before You Dig service makes sure people don’t place a garden over, or dig up, any buried essential services such as gas lines and communication wires. Street gardens also need to be in containers higher than 50cm to prevent people tripping over them.

Mark Driver, a parks and recreation planner at the City of Sydney, says the policy was driven from the ground up: “People were writing and calling council asking if they could put planter boxes outside their house, and were starting to do it anyway.”

Walking around the city, Mark can see more planter boxes as a result of the policy. All it takes is one person doing it for others to quickly catch on. “Some streets in Sydney that started with just a few people now have a streetscape dominated with gardens and a community has developed around that,” he says.

Jock Keene planted some raised garden beds on a busy city footpath in Glebe, Sydney. He began these gardens before the council guidelines were introduced and thinks the council is doing the right thing by making it easier for people to start them. He says the most important guideline is making sure all your neighbours are happy with the garden.

Jock has placed three wine barrels and three wicking beds on the street. In them he grows a range of veggies including cucumbers, kale, beans and rocket as well as about 25 herbs around a street tree. People are encouraged to pick what they need and a seat provides a spot to rest and meet others.

In such a public space, you really have to give up ownership of the garden, he says. If someone takes something, it’s gone to a good home and he’s happy. He adds that you have to resist putting up any berating signs that are negative such as ‘Don’t pick these until ripe’. Tomatoes will go as soon as they are just a little pink and that is the way it is.

Design for heatwaves

Climate change is with us and no achievable amount of mitigation is going to reverse its effects sufficiently to prevent our need to adapt. Australian houses today are largely designed or modified based on historic climate data, even though we (or someone else) will be living in them for at least 50 years. Quite simply, this approach is inadequate in a rapidly changing climate. While we will no doubt survive the two to three degrees of warming already locked in, we urgently need to re-think our approach to housing to cope with the extremes.

Hotter for longer

Heatwaves of increasing frequency, intensity and duration are occurring in the southern half of the nation and have already killed many hundreds of people. CSIRO and the Bureau of Meteorology predict that these will increase exponentially. We will not be able to cool or air-condition our way through these crises.

Heat waves are regional events. When we all cool our homes at the same time, we cause electricity demand to peak and, on top of increasing electricity costs, grid failure becomes increasingly likely during peak demand periods. Homes without an alternative coping strategy will become uninhabitable at best. While those of limited means will likely be most severely affected due to cooling unaffordability and poor home design, comfort moves beyond the reach of everyone when the grid is down.

Australian cities likely to experience increasingly severe heatwaves include Melbourne, Adelaide, Perth, Launceston and Hobart as well as most south-eastern regional areas. These climates traditionally require significant amounts of heating in winter. Our standard design response to date has been to apply passive design principles, relying on significant amounts of thermal mass.

This approach allows dense materials to store daytime warmth from the sun and release it into living spaces at night to offset the coolest temperatures in winter, and night purging during summer to take advantage of cooler outdoor temperatures.

As the climate warms and winters become shorter, homes in these areas will require less winter heating and more summer cooling. In many of these climates, night purging via cross ventilation and convection (internal hot air rising and exiting that in turn draws in cooler night air at floor level) would become gradually less effective. During heatwaves, temperatures can remain well above comfort levels all night – eliminating any passive cooling opportunities. Under these conditions, the temperature of the thermal mass would increase substantially and take many days to cool down when a heatwave eventually passes.

While many regions in our southern states will have heating-dominated climates for decades to come (where more energy is used for heating than cooling), the following suggested measures will also help keep homes warm and remain prudent investments.

Read the full article in Sanctuary 29 to find out how glazing, building envelopes and planning and zoning can help future proof your home.

Chris Reardon, co-author of this article, passed away last month. Read more about his work promoting sustainable design here