Published in Sanctuary magazine, Issue 11
Words: Jane Canaway
A shady place to read; somewhere to catch the sun; a flat spot for games; lawns can provide all these and more, but their cost in terms of water use and maintenance has relegated them to the bottom of the green league.
Luckily, canny landscapers have been busy devising clever alternatives, including drought-tolerant turf and native grasses.
When considering the various options, gardeners should consider what it is they most want from a lawn. Should it be a place to play or to entertain, or do you want a lawn for purely aesthetic reasons?
If your aim is to create an area of low-growing, lush greenery to set off surrounding beds, then groundcovers may suffice. “I like to use Myoporum parvifolium to create an area of green contrast, with stepping stones set into it,” says garden designer Wendy Clarke who, after training with Sustainable Gardening Australia, is accredited to offer environmental advice. “You can’t walk on it but it has pretty pink flowers in spring and it looks lovely all year round.”
Other hardy plants that create a dense cover include many saltbushes (such as Atriplex semibaccata, Enchylaena tomentosa and Einadia nutans), which are also fire-retardant and provide habitat and food for skinks.
Many non-grasses will not tolerate traffic, but the new fine-leafed Lomandra cultivars are impressively hard wearing. Garden designer Liz Turner used it to great effect to replace some dead lawn around a trampoline. “The site is in full sun and the soil was pure clay so I dug in lots of compost first, then planted it out with Lomandra ‘Lime Tuff’,” she said. Two years later and despite heavy use by four boys and a Labrador dog the soft, tussocky mounds are looking lush and healthy.
If you worry about embedded energy costs in petroleum-based products, skip this section, but if a perfect green sward is your thing, read on.
Pros of synthetic turfs include year-round colour, shade-tolerance, a mud-free edge to pools, great drainage, rain-permeability and no mowing. Cons can include high upfront cost, heat retention, limited warranties, sterility – synthetic turfs produce no oxygen and provide no habitat – and the need for maintenance.
For high traffic areas, timber decking or stone paving may be preferred. A major consideration, however, is the extra heat pavers retain on a hot day. Shading a paved area with a deciduous tree or carefully designed pergola can help. “I try to reduce the amount of hard surfaces I use,” says garden designer Phil Johnson. He stresses the importance of considering stormwater: “You need to think about using the run off; if you get in early in a project you can also collect the water from underneath by using permeable surfaces so it drains through.”
When nothing else will do:
Native grasses have low water use, provide great habitat for all forms of wildlife and can offer interesting colours (red leg grass), seed heads (wallaby, kangaroo, windmill and spear grasses) and textures (silky blue and plume grass).
However, most are grown from seed (the deep roots make turf production difficult) and develop slowly, so need patience, hand weeding and some watering until established; chemical broadleaf herbicides are not recommended for the first few months.
Also, because many are tussock forming or have only short rhizomes they are slower to regrow if damaged by heavy foot traffic. Two showpiece lawns have been sown at the Royal Botanic Gardens, Melbourne, where they survive well but daily footy matches are not recommended.
At most, native lawns will only need mowing up to six times a year – usually to remove seed heads – and the blades should be kept high, around 25-40 mm. Weeping grass may benefit from an application of fertiliser if the leaves show some yellowing, but redgrass and wallaby grasses rarely need it. All will appreciate watering but have much lower needs than exotic species.
“Microlaena stipoides (weeping grass) is the best native lawn grass,” says Phil Johnson. “Having said that, we need to educate people about what is an acceptable-looking lawn. I don’t like a scruffy look, so I choose Microlaena, but I can still see the beauty in an expanse of Danthonia (wallaby grass) with flower heads blowing in the wind.”
NATIVE GRASS VARIETIES
* Microlaena stipoides (weeping grass) will survive frosts and extended hot, dry periods, but may lose leaf if not watered during these times.
* Austrodanthonia (wallaby grass) is heat and drought tolerant, green all year round and hardier than weeping grass.
* Bothriochloa macra (red grass) is heat and drought tolerant. It is adapted to acid soils and low fertility soils.
Ko-Warra Native Grasses – www.nativegrasses.com.au; (03) 5480 9778
Native Seeds Pty Ltd – www.nativeseeds.com.au; (03) 9555 1722
Drought-tolerant Exotic Turf
If you want a lush green lawn and you can’t live with a native lawn then the following turfs have been developed for Australian conditions:
* Sir Walter buffalo is one of the best for Australian conditions and lifestyle, combining soft texture with resilience and low water use.
* Buffalo Sapphire is a warm-season grass. It reportedly retains good winter colour in most southern states but will become dormant in colder areas such as Canberra.
* Matilda is a semi dwarf buffalo that is recommended by NSW-based Bill’s Turf Supplies as one of the most drought-tolerant grasses. It tolerates full sun, part shade up to 80 per cent, temperatures below zero, salty soil and clay and rocky soils.
Bill’s Turf Supplies
02 8999 7684; www.billsturfsupplies.com.au
turf, including Matilda, empire and Durban
Buchanan Turf Website
1300 554 442; www.sirwalter.com.au
Sir Walter buffalo
1300 25 2000; www.ozbreed.com.au
sapphire, native species and strappy plants
Exotic lawn maintenance
“Anyone can have a lawn if they reduce it to a sustainable area and use whatever water is on site,” says Phil Johnson. Harvest as much water as possible, including stormwater and greywater. Wendy Clarke estimates 40,000 litres can sustain up to 40 square metres of lawn, based on an average rainfall of 650–700mm.
Preparing the soil for a lawn is also important. “Normally I avoid having too much sand in soil, but for lawns you need a fair bit to avoid the soil becoming too compacted,’’ Wendy says. “To make sure the soil can still hold enough water and nutrients, I always use Hydrocell water retaining foam and try to get as much organic matter into the soil as I can.”
Adding sand to soil will permanently improve its drainage. Gypsum dug into clay soils will improve friability and drainage by chemically binding the super-fine clay particles together to improve drainage.
Turf is best laid in spring; if warmer weather cannot be avoided, help it settle in by deep watering with Seasol or similar shock-reducing fertiliser, and regular watering.
Then there’s maintenance. “One of the most important aspects of having a lawn is how you mow it,” says Phil. “The easiest way to kill a lawn is to mow it so low that the roots burn and the soil dries out. Keep it long and lush and it can retain more water that way.”
The national website of the Savewater! Alliance, www.savewater.com.au, recommends using a slow-release fertiliser once a year and a liquid boost as needed.