James BeattieHow to grow a native Australian grassland

This article is the first in a two part series on establishing native Australian grasslands in a garden context, specifically for nature strips in the Melbourne area.


A great example of the prairie school – Frogmore Gardens here in Australia

 

Prairie and meadow styles of design have enjoyed a huge interest from gardeners in the last 20 years, and little wonder. Who doesn’t love the delicate ballet between blocks of breeze-catching texture punctuated by drifts of subtle colour? The most beguiling aspect of this burgeoning popularity in Australia for me has been the almost complete lack of popular interest in our native grasses to achieve a similar aesthetic. In Australia we have an ecotype that beautifully mimics a prairie-style sensibility – our own native grasslands – once biodiverse wonders that blanketed vast swathes of temperate regions throughout the southeast of our continent.

An intact, but not well-managed local grassland with chocolate lilies and yam daisy adding seasonal colour.

 

There are so few well-managed grasslands left that people can go and see themselves, which goes a long way to explaining their absence in our gardens. In Victoria, where I live, less than 1% of grasslands exist compared to their previous range. As gardeners we often ‘ooh and aah’ over rare plants we grow, the vast majority of them exotic, but there are a plethora of local, indigenous grassland plants that are just as deserving of the title. A sound way of ensuring their existence into the future is to grow them yourself.

I set out to try and create a native grassland, turning my nature strip over to native grassland plants just on 20 months ago. The results have been incredible, I’m very pleased with the way it’s shaping up.  Aesthetically I think it a very beautiful thing, though I’m sure some pedestrians probably walk past it and wonder when that skinny bloke is going to mow his bloody grass.  Far more stop and linger to take a closer look, some delight further still by asking questions.

 

You really need to want one in order to have one, they’re not easy things to establish and their maintenance requires more ecological than gardening-thinking. They take effort and careful planning, but then what good garden doesn’t? I worked in bushland management for several years, managing and monitoring some wonderful little patches of remnant grassland around Melbourne. The experience was a steep learning curve, requiring a horticology approach rather than an ecological or horticultural one. It was often tough graft, but the time spent was invaluable. Getting to know patches of grassland around your area is a great start*.

While native grasses such as ‘poa lab’ (Poa labillardieri) have been in the collective conscience for a number of years, many other grasses have missed out. Broadly speaking, there are several genera of garden merit that make great additions to grassland-style plantings. These include, but are by no means limited to, the wallaby grasses, Rytidosperma spp. (formerly Austrodanthonia spp.); the spear grasses, Austrostipa spp.; kangaroo grass Themeda sp.; tussock grasses, Poa spp.; and plumegrass, Dichelachne spp. As a collection of genera they represent hundreds of species to choose from. They make up the bulk of grassland biomass, though this list isn’t comprehensive by any means. My advice is to learn about them, what they look like and how they grow. They’re all different and provide a myriad of textures and colours at your disposal to design with.

Dichelachne micrantha at the Geelong Botanic Gardens. This is one of the must underused of all Australian grasses!

 

All of the above grasses give great value over a long season. Whether they’re gearing up to flower, setting seed or have long dehisced it, like all grasses they go through seasonal changes several times a year and look ornamental at every single one. My favourite time of year in my grassland is late summer. There’s not a lot of colour around as the weather’s very hot, but the wallaby grass species I have planted retains its glumes, its empty seed heads, for months after the seed is shed. Glumes on mass in the afternoon light, catching a zephyr, look as stunning as any flower you’ll come across.

High summer in my grassland. The glumes of wallaby grass and spear grass on mass make a striking effect.

 

Why Should You Want a Suburban Grassland?

Apart from there not being much of them left and their aesthetic beauty, once established (the tricky bit), ongoing maintenance is really very easy. Once you get a good coverage of grasses they are highly effective at choking undesirables out. What weeds do grow are easily noticed and hand-pulled. Furthermore, native grasslands don’t require any supplementary irrigation at all.  The vast majority are soundly perennial – they will often brown off, almost completely in summer, which is a an ideal time to give them a mow.  They will readily reshoot when cooler, wetter weather returns.  Most of them ‘recruit’ readily – they easily spread by setting seed. Establishing them well is all about getting your timing right with planting/sowing. Get this right and you’ll only have to water your plants in – they’ll never see the nozzle end of a hose again.

Native grasslands have huge biodiversity values, not just for the plants they contain. A vast number of insect species call grasslands home, many exist only to visit specific plants, which is remarkable. One of many examples: I have a couple of species of native bee that visit mine which are known to feed exclusively on wahlenbergia flowers. Many other similar relationships exist in my grassland and for every insect I identify there are probably a dozen more I don’t even see. A diversity of insects means a large population of potential garden helpers that will often help keep the populations of other problem insects in check. Toward the end of winter for last three years, I had massive problems with aphids on a Veronica perfoliata in my front garden. I haven’t seen any at all these past two years and I suspect the new grassland and its residents are probably responsible. These unseen helpers make pest management in the rest of my garden easier. Where they come from and how they find their way to a 2.5m x 8.5m patch of land in the middle of the northern suburbs of Melbourne is a great mystery to me, one I would like to solve, but I’ll also be content with the romanticism of continuing to wonder in the meantime.

 

Prepping Your Strip

Before you do anything check your local council’s rules around naturestrip gardening. They vary considerably between municipalities, most require a permit and others may even slog you a fee for the privilege. For Melbourne specifically, site prepping is best done in late summer/autumn/early winter, whilst aiming to plant in late autumn to winter (when rainfall is reliable and plentiful here) so get your permissions in order well beforehand.

It’s also advisable to think about foot traffic and put in a little bit of infrastructure to direct it through your strip. Many a nature strip gardener has torn their hair out at people trampling their plants. My advice on this front it to put in a couple of paths – people will use them instead of walking through knee-high grass, but not always! At the end of the day a nature strip is land that people will always cut across. For you own sanity just accept that this will happen, as getting a bee in your bonnet every time you see a person traipsing through it will only lead to a cultivation of madness, and others may see you as a bit unhinged.  Let it go.

So you’re looking at your nature strip as a potential grassland – what do you see there now? There’s probably grass and likely a few different species of it. Kikuyu is common in Melbourne’s nature strips, as is Ehrharta erecta (panic veldt grass), couch, and winter grass (Poa annua) waiting to pop up once the weather cools off. There are likely broadleaf weeds too, such as dandelion species, flick weed, oxalis, chickweed and pimpernell, among many, many others. The critical thing to understand at this stage is that all these plants have been dropping seeds into your little strip far longer than you’ve been eying it off as a potential garden. There is a sleeping army of thousands (millions?) of seeds just waiting to germinate and cause you grief. Grief bears an inverse relationship to enthusiasm – a parlous state that will put your grassland at risk in the future. Avoid it as best you can.

To make the establishment of your grassland as least stressful as possible, your existing nature strip grass needs to be cleared and this weedy seed load dealt with somehow. You’ve three main options on this front:

  1. Scalping the soil, taking at least the first 75mm (3 inches) off, seed load with it, and getting rid of it (expensive but highly effective in controlling weed seeds).  A turf cutter does this job brilliantly well.
  2. Solarising the whole area by placing black plastic over it for several weeks in late summer – this will cook a large mount of the seeds, though not all, as well as kill grasses and broadleaves (effective on some weeds, but not all, and it looks atrocious). Steaming might also work but I can’t vouch for its effectiveness.
  3. Herbicide is another option (judgment on the ethics of their use should be suspended for the purposes of this article). It will clear grass and kill the weeds that are growing, but it won’t deal with the weed seed load at all. This option requires intensive hand pulling as weeds come up, mainly during winter.

Weeds killed off and simple pathways about to go in.

 

Deciding which you use will depend on your budget and the amount of effort you are prepared to put in. The bushland manager in me saw me using the last – killing off my kikuyu with herbicide and hand weeding what popped up. I spent a lot of time weeding, time that would make well-hardened gardeners shriek in horror. But there are two reasons why I went down this path.

Firstly, I rather enjoy weeding, especially with a beer in hand. The second is that hand weeding means you are down there on your hands and knees regularly, right at the coalface of your changing ecology, watching it and making observations of the little differences that emerge week-by-week. You constantly learn about the plants and the way they grow together, often without realising it. If you hand weed you will soon be able to tell the difference between goodies and baddies, like a weedy Poa annua seedling and a local wallaby grass seedling.  The phrase ‘getting your eye in’ applies here in a big way. If you get your eye down to this level and pick up those differences you’re well on your way to a successful suburban grassland of your very own.

If you’ve got this far, well done!  I’m happy to answer any queries on the topic of site prep.

The next instalment will cover selecting species, planting, maintenance and a controversial question: to mulch or not to mulch?

Until next time, happy gardening.

 


*Local grasslands around Melbourne.  The following list and links are those good for exploring and observing throughout the year, hitting their aesthetic peaks in late spring through to mid-summer, they include:

 

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James Beattie

About James Beattie

James is a horticulturist working in the Melbourne area. His work in the industry has included landscape planting design, hard landscaping, bushland management, garden consulting as well as extensive experience in the horticultural media. He worked for four years as one of the horticultural guns for hire behind the scenes at ABC TV's Gardening Australia program and has been a semi-regular guest on Melbourne's 3CR Gardening Show (855 AM). You can follow his whimsical garden musings at Horticologist

9 thoughts on “How to grow a native Australian grassland

  1. carlogabriele on said:

    A truly killer article: well thought and well written. I am trying to write something smart but, honestly, you said all you needed to say.
    I admire your approach which is all about using what you have than copying something else because it’s exotic. Some weeks ago I saw the umpteenth copy of an Oudolf garden realized here in Australia. It looked so fake and out of context! Same feeling with North American or European trees in the country, especially now that they change colour and the surrounding landscape stays brown.
    Bravo!

    • James Beattie on said:

      Hi Carlo,

      Thanks for the comment.

      Our native Australian grasses do seem to ‘fit’ our landscapes in many ways whereas exotics tend to stand out. But therein lies their beauty! Many of our grasses remain untested as garden subjects, and those that have been tested tend have generally been in the context of a foreign aesthetic. My attempts are aimed at developing a uniquely Australian aesthetic where our grasses are concerned.

      I’m by no means the first to dabble with our grasses. The work Chris Findlay from Flora Victoria and Dr Ian Chivers from Native Seeds Pty Ltd is impressive, and much larger in scale. Oh to have a few acres in which to experiment more! One day soon. I’m looking at property as we type.

      Cheers

  2. Michael McCoy on said:

    Thanks James for this fabulous post. So good to know that someone is playing with our Aussie plants in this way. Really looking forward to the next.

    It really (and sadly) seems like there’ll never be any commercial imperative for anyone to explore the potential of Australian grasses for such planting as yours, which makes your work all the more critical.

    One of the biggest challenges that I’ve had personally is trying to establish a management regime for these grasses that allows them to look really good for more than, say, the first four years. I understand that grasses no longer seem to be categorized into deciduous and evergreen, and are classified as either warm season or cool season, but the great implication of true deciduousness is that it allows for a total annual cut-back, virtually to the ground, without any diminution of vigour over time. I interviewed James Van Sweden in about 1998 on ABC o’night radio (talked to him for about 45 mins! Only possible on o’nights!), and he said that their planting of the Federal Reserve garden was then 23 years old, and none of the perennials (including the Miscanthus species) had been lifted or divided in that whole time!

    I’ve not found the ‘evergreen’ grasses to be nearly so accommodating, which is perfectly understandable, given that an evergreen grass (and I nervously waver from science here) isn’t going to retract all of its nutrients at any particular point of the year, and a brutal annual haircut is (I assume, and with empirical evidence only) going to eventually deplete the plant to its detriment, and eventual death.

    Having said all of that, once when I was gazing longingly at a huge stand of grasses at Chelsea Flower Show, I asked the exhibitor which of his many species was the most underrated, or at least had the most underexplored potential. Without a hesitation he answered ‘Poa labillardieri’!.

    • James Beattie on said:

      Thanks for the comments, Michael. Thought-provoking, as always.

      I’ve spoken to two of the Victorian leaders in this field in the past, Chris Findlay of Flora Victoria and Dr Ian Chivers from Native Seed Pty Ltd. They echo your sentiments. Drumming up commercial interest is an uphill battle, but they keep going regardless because they see merit in native grasses, especially for larger landscape projects. They both have a lot to say about the potential of these grasses, it’a well worth a chat to either of them.

      I will touch on cool/warm (C3/C4) season classification of our native grasses in the follow up article. It’s an important distinction.

      The longevity of the cool season grasses is an interesting point. I’ve made the same observation in the past and am trying a few different design combos/specific plants to (hopefully) get around it. Using cool season grasses like wallaby grass is a very handy way to overcome a lack of longevity of the larger clumping grasses, which have traditionally made up the bulk of native grassland-style plantings in the past. The large clumping grasses on mass, for me, is a mistake for exactly the reasons you stated.

      Wallaby grasses are prodigious seeders, and if the hard annual cut back sees you lose a few, there will always be replacements germinating to take their place, provided you don’t mulch (controversial! I talk about this at length in the follow up). In this sense the wallaby grasses are more like an annual or a short-lived perennial. They are sterling performers at recruiting themselves.

      The general idea with my planting is that the main biomass, the wallaby grass, is self-sustaining from seed if/when the perennial parents give up the ghost. The larger clumping grasses are in there only to break up the massed effect of the wallaby grass and to direct foot traffic, not as the main feature. I thoroughly de-thatch the poa at the end of summer and give it a 1/3 haircut to neaten it up – as you say, being as brutal with it as you would many exotics seems to gradually kill it off.

      It’s still early days, but so far so good. It’s certainly developing the way I envisaged so far, but I’m refining it all the time, tinkering around the edges – as we do with any garden!

      And Poa lab in the UK – most underrated! Well, I never! Perhaps their climate promotes a much less thatchy, more well-behaved plant in the long term? Were they using improved forms that you are aware of?

      Thanks again.

      • Michael McCoy on said:

        As for Poa lab in the UK, this guy was unaware of any improved forms. This was nearly a decade ago, and the only named form I was aware of at the time was ‘Suggan Buggan’. He was very interested indeed, and took details of Lambley nursery in the hope of chasing it up. I wasn’t then aware of ‘Eskdale’.

        But what’s interesting is that he treated it like a full-on deciduous herbaceous perennial, and cut it very hard in early spring. I’ve found that to work best where I am, and Michael Cooke treats his in the same way in a cooler part of NSW. I wonder if there’s a tipping point of winter minimums, and therefore of apparent ‘dormancy’, that allows it to be cut hard in spring in some regions and not in others (where it may have already done much of it’s annual growth during winter)?.

        Dang. Don’t you wish there was some institution here in Australia charged with the responsibility to sort this kind of stuff out?? We really need the Aussie equivalent of Wisley…

  3. Eugene on said:

    Excellent, timely article James and I thank you for it. Think you have touched on a thing here that is ripe for exploration. Wish I had the acreage to join in the fun, but all I do have is a tiny green roof 1m x .8m x 250mm deep that I thought would ideally suit some frothy, light catching grasses. I love Stipa gigantea, but a bit bored with it now and so wondered if Themeda triandra or Poa lab would be worth a go? The roof will be just above eye level, a slight slope and mainly viewed from against the light. Any thoughts you may wish to share will be greatly appreciated.

    • James Beattie on said:

      Hi Eugene,

      I’m really keen on the wallaby grasses as ornamentals. Some of our local spear grasses are garden-worthy as well. For green roofs especially, I’d recommend kneed wallaby grass (Rytidosperma geniculatum) – it’s low-growing and will form a nice carpet topped with sumptuous amounts of flowers/glumes over many months. It seeds embarrassingly well, which it regenerates from very well if the parent plants die – which they might do on a green roof.

      As far as spear grasses go, Austrostipa elegantissima looks wonderful on mass. Large feathery heads of flowers, not entirely unlike the smokiness of cotinus. Austrostipa rudis is another winner, with tall flower spikes that look great punctuating the lower-growing wallaby grasses.

      Austrostipa stipoides is one of my all time favourites. I always think of it as a much more handsome and robust/architectural poa lab – the blades stand straight up and have wonderful russet tones. It does get larger than poa lab though. It’s a coastal native and I’ve seen it growing happily in some remarkably crappy, sandy soils. However, I can’t vouch for its veracity in a green roof situation – but given its natural habitat, it’d be worth a shot.

      • Eugene on said:

        Thanks for that James. The Rytidosperma will certainly be in the mix as I note that the seed is favoured by the firetail finch and given that the green roof will be adorning my soon-to-be-built finch aviary, I think we got a beautiful thing going on right there. 🙂

        I’m familiar with Austrostipa stipoides from Corner Inlet at the Prom where it cuts a fine figure. I used to wade through it’s caramel gorgeousness to get to a neat landbased fishing spot. Didn’t know what it was till you made me look it up. That will certainly get a look in too. Last year I was struck by some Oudolf inspired images and so started taking note of the grasses, weeds and neglecterinos in some of the paddocks and industrial wastelands in these here parts. There is often wonderful surprises to be found in the most unlikely spots and it’s funny how what you once took for granted, can suddenly assume such grace and beauty once you’ve been nudged into seeing it. I shall look out for your nature strip! Many thanks again.

  4. hilary10 on said:

    Yes! Thank you James! I have been establishing a rural garden for the last 3 years and have spent many evening hours gazing at Piet Oudolf’s foamy masses of grasses but have been left feeling hollow in my own garden the next day. All those European perennials just don’t seem to be the right foreground to a background of eucalyptus. So thank you kindly for your guidance on how to achieve a native grassland and I look forward to reading about it more. I hope this can become the ‘new native’ style.

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