Matt Cantwell garden, Cronulla, NSW

A striking house needs a garden to match.

Matt Cantwell garden, Cronulla, NSW. Picture: Nicholas Watt

“Locals call it the spaceship house,” says Matt Cantwell, whose company Secret Gardens was responsible for creating the equally arresting gardens around this landmark residence.

Situated on a double block on the southern tip of Cronulla in Sydney’s south, the futuristic home, completed in 1973, has views across Port Hacking to Bundeena from its coastal perch. Australian architect Reuben Lane designed it without visible right angles, influenced by his time working with Brazilian modernist Oscar Niemeyer.

Matt Cantwell garden, Cronulla, NSW. Picture: Nicholas Watt

The owners, who have “exquisite taste and knowledge of mid-century architecture, furniture and art” according to Cantwell, embraced the opportunity to restore the house and develop a garden that would be part of the house’s identity.

“Surprisingly, there was very little existing landscaping and few plants,” he explains. “The land sloped steeply to the water from the house and felt detached from it. We wanted to entice people out into the garden.” He took his design cues from the building, using a combination of curves and angled lines to carve the slope into usable spaces that deliver an equivalent sculptural impact.

To fit in a long pool, Cantwell tucked it partially under the house rather than have it (and the requisite safety fencing) dominate the coastal strip and views from the house. Its glass end allows for impressive lighting effects at night, while the glass fencing, some of it curved, is as subtle as possible.

Matt Cantwell garden, Cronulla, NSW. Picture: Nicholas Watt

At the other end of the garden is the “destination fire pit” area. “We wanted to make it visually striking and echo the round shape of the house,” says Cantwell. He positioned it to take advantage of the longest view across the water and be protected from cold, southwesterly winds.

The project’s greatest engineering challenge was to link these two elements and make an interesting journey through the garden. Five circular pods of lawn were created, each elevated circle stepping up with the gradient.

Between the garden’s angled walls, rendered with stucco to match the house, is a selection of bold foliage plants including aloes, Furcraea, Agave americana and grasses that can withstand the salty winds. Natives such as lomandras and banksias are used closer to the water; Livistona palms complement those in the adjacent nature reserve.

Matt Cantwell garden, Cronulla, NSW. Picture: Nicholas Watt

Fronting the street, a striking row of cactuses – tall and barrel types – attract the attention of passers-by. Well below street level, Cantwell created an “entry experience” with a large water feature under the bridge leading to the front door. The sheltered conditions here allow lush tropical-style plants to thrive.

The project, completed in late 2018, took eight months and won a commendation in the 2019 Houses Awards. “It was complicated to build but we were really lucky to work on such a unique house with an enthusiastic client,” says Cantwell.

Q&A

We removed a row of huge yuccas and poisoned the roots with blackberry killer. How long should I wait before I replant? Jude Hines, Adelaide

Triclopyr, the active ingredient in blackberry killer, has an average half-life of 30 days but this can vary from four to 314 days. It photo-degrades in sunlight; microbial degradation is fastest in warm, moist soils. The label says sprayed plants should not be burnt, cut or cleared within six months. But the dense stump and roots left behind may prevent replanting; they can take years to rot. A stump-grinder could grind the area to 50cm depth; remove the sawdust and replace with fresh soil.

A friend helping to pick lemons says I should cut the middle out of the tree now for easier access to fruit from the highest branches. I usually prune in autumn. What’s your advice? Helen Joske, Hobart

Regular, light pruning to keep the tree easily reachable for spraying and harvesting is sensible. It also helps productivity. The best time to prune is after harvest in early spring. Opening up the centre of the tree occasionally can help increase light and airflow for better pest and disease control.

How frost-sensitive are Norfolk Island pines? I have 10 in pots waiting to plant in an open paddock that often gets to -1°C in winter. Brian Reader, Nelligen, NSW

Araucaria heterophylla is hardy down to the zone of -6.6 to -1C. In other words, they tolerate light frosts. Ideally, wait until spring or be prepared to give frost protection on cold nights.

Organic Gardener 18-month subscription, worth $96

Send your questions to: [e-mail] or Helen Young, PO Box 3098, Willoughby North, NSW 2068. Website: helenyoung.com.au. The best question for August wins an 18-month subscription worth $96 to Organic Gardener magazine, celebrating its 20-year anniversary.