Recreating the Country blog |
Restoring native grasslands - where to start? When faced with a daunting challenge like restoring native grasslands from a patch of bare earth or a paddock full of exotic weeds, sometimes the wisdom of a great sage can light the way forward. I couldn't do better than the often quoted words of the Taoist philosopher Tao Tzu; ‘The journey of a thousand miles begins with a single step’, His well-chosen words help to shrink the broad focus of a big challenge like grassland restoration, to a goal that is much more achievable. Though in the context of grasslands, Tao Tzu might have said; ‘Restoring a native grassland starts with sowing a single seed.’ Glimpses into the past - What history can teach us? The year is 1883, a little over forty years after Victoria’s ancient and fragile landscapes first felt the pressure of thousands of hard-hooved animals. Pioneer Edward Curr witnessed that indigenous grasses were already in rapid decline; ‘The most nutritious grasses were originally the most common; but in consequence of constant over-stocking and scourging the pastures, these have very much decreased, their places being taken by inferior sorts of weeds introduced from Europe and Africa.’ The signs of degradation and loss could be seen at the beginning. Edward Curr describes a destructive and careless system of farming that would have caused the loss of many plant species and the ecologies that they supported. What John Batman saw John Batman sailed into Port Phillip Bay and walked ashore at Indented Head on the Bellarine Peninsula on 29th May 1835. He wrote in his diary; ‘…nearly all parts of its surface covered with Kangaroo and other grasses of the most nutritive character, intermixed with herbs of various kinds.’ It’s surprising that Batman was able to make these enthusiastic observations in late May, which is a time when the spring blooms of wildflowers are long gone and most indigenous plants are dormant. Many are hidden underground as tubers or grasses and herbs that are no longer looking at their best. Two days later, after a 32 km walk east from Point Henry, Batman described the vegetation on Mt Bellarine; ‘…very rich light black soil covered in Kangaroo Grass two feet high and as thick as it could stand, good hay could be made in any quantity. The trees were not more than six to the acre, and those small sheoak and wattle. I walked for a considerable extent and (it was) all of the same description.’ It’s likely that Batman had one eye on the rolling hills of the Bellarine Peninsula and the other on marketing his proposed new settlement to the members of the Port Phillip Association. We know he promoted the landscapes around Geelong very well, from the tidal wave of new settlers that arrived soon after his deceitful and fraudulent 'land purchase' from the Traditional Owners, who would never have agreed to hand over the lands of their ancestors. The changes to grasslands were swift and overwhelming The rapid changes to the vegetation around Geelong are shown by the early loss of an important staple food of the Wadawurrung. It took only four years for the women of the Bangali Clan of the Bellarine Peninsula to report that the Yam Daisy, once plentiful and widespread, had already become difficult to find. This same intense grazing pressure from flocks of sheep, their population doubling every three years, would have affected other plants with edible roots like the Chocolate Lily, the Bulbine Lily and all the species of orchid. We know that the sheep were so fond of these edible roots that they unearthed them by digging with their hoofed feet. The leafy herbs would have also succumbed to this new and much more intense grazing pressure of sheep and cattle. Only the toughest and least palatable of the native grasses and forbs would have survived this severe level of disturbance. The plants had evolved with kangaroos, wallabies and emus that grazed more lightly for a shorter period and then moved on, creating a grassland mosaic of different ages and lengths. A more recent story illustrates how gradual change can be just as devastating to grasslands. The Sunshine Orchid, Diuris fragrantissima, described as dizzyingly beautiful, was so prolific in the western suburbs of Melbourne that it was known as 'Snow in the Paddocks'. An indigenous woman could dig enough of its sweet tubers in one hour to feed her family for a day. This regular harvesting with digging sticks made the soil loose and spongy, according to early settler records - a far cry from the hard and compacted basalt soils west of Melbourne today. Before the 1950s, locals would collect large bunches of the orchid blooms for their fragrant flowers. These orchid rich soils were ploughed, scraped, compacted, subdivided and finally built on. Now there are only 37 closely guarded Sunshine Orchid plants left alive in a location that remains a well-kept secret. A 'new' fire changed the vegetation The termination of Traditional Owner management practices would have also changed the composition of the ground flora. Early settler descriptions of the burning practices on the Bellarine Peninsula give important insights into their cool burning method; ‘…their burning practice was random enough to maintain a wide variety of plant species and to keep the woodlands of the Bellarine Peninsula open and grassy.’ This all changed soon after 1835 when fires across the Victorian landscape became much hotter. This would have had a substantial effect on all native plants. In February 1851, one-third of Victoria endured perhaps its first destructive wildfire for millennia. Many flora and fauna species would have declined and disappeared under the unfamiliar forces of this new pattern of uncontrolled and hotter fires. Note on studies of historic fires: Core samples of lake sediments show that carbon levels increased dramatically soon after the white races occupied Australia. These studies provide clear evidence that the practice of strategic Traditional Owner cool burning prevented the out-of-control hot fires that have become a familiar and devastating manifestation of our Australian summers. Do we know what our local vegetation looked like before 1835? To give you a sense of what was here before, native 'grasslands' could have been more accurately described as 'pantry-lands' or 'medicinal herb-lands'. This is because the Traditional Owners managed grasslands for their traditional uses as food and medicines, as well as the ecologies that the diversity of plants supported. Some of our best examples of remnant grasslands are found on roadsides, sustained by annual CFA burning to create firebreaks. Though, their practice of spring burning favours some plant species over others that need autumn burns, less frequent fires or cooler burns. This can be seen at the Rokewood cemetery, which is dominated by native herbs like its famous Button Wrinkewort, Rutidosis leptorrhynchoides, and has fewer native grasses. The annual spring CFA burning pattern has prevented grasses and some forbs (definition below) from flowering, setting seed and reproducing. This isn’t a criticism of the fine work that generations of country firemen and women have done to maintain this grassland and reduce fire risk locally. Their work has helped us understand how different patterns of burning can favour various plant species. Considering the dramatic changes in grazing pressure and burning temperatures since 1835, it’s probably not possible to find pristine remnant grasslands, exactly like those that were present two centuries ago. My own view has changed and I am now tempted to say that the composition of modern remnant grasslands is likely to be quite different to what was here pre white settlement. I feel we have very likely lost more species than we like to admit and the species grouping within plant communities has changed significantly. So here it is in a nutshell; ‘The remnant indigenous grasslands of Victoria, that we consider being in good condition, are likely to be floristically quite different to the grasslands that existed before the white races arrived in 1835?’ (A forb in botany is a flowering native herb. It excludes grasses, sedges and rushes as well as woody stemmed plants like shrubs and trees. Here is this handy rhyme to help you appreciate an important difference between a sedge, a rush and grass - 'sedges have edges and rushes are round, grasses have elbows that bend to the ground') To some of you, this may be an heretical statement, to others I’m likely stating the obvious. Though, it leads nicely into my next suggestion; Perhaps it’s time that we accept that we can't turn back the clock to a time before 1835. We should protect all surviving grasslands of course. The time has come to create new, robust and ecologically diverse modern versions of the 'lost grasslands of Victoria'. If we lay the right foundations and manage them with Traditional Owner style cool burning, Mother Nature will step in and guide its evolution towards a healthy sustainable balanced mix of species. Tao Tzu has something wise to say about this proposition as well; ‘Nature doesn’t hurry, yet everything is accomplished.’ In Restoring Native Grasslands - part 2, you can read the success stories of scientists and farmers who have restored grasslands. In Restoring Native Grasslands - part 3, I’ll set out a simple method of replanting native grasslands. Here is a glimpse of part 3; You have returned home from a community meeting, inspired to plant a native grassland on your own back lawn. After a morning of weeding, you have carefully removed all the grass from a patch the size of your four-year-old’s paddling-pool, so that it’s now loose bare soil. Your grassland champions from the nursery are well-watered and ready to plant, and a group of friends will soon arrive to be part of what promises to be the beginning of a new era. An era when the local plants begin to return to backyards across the country. Curiously, you have a 2 kg bag of white sugar to spread on the soil before you plant. Sweet ??!! You and your friends are part of a new nationwide movement to restore the lifeblood of the land – by planting back the remarkable plants that have made Australia so floristically unique. For some background reading on grasslands - Grasslands. Why we're losing the battle to save them
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'The interactions between plant roots and their symbiotic mycorrhizal fungi are quite intimate. Root exudates lure compatible fungal threads while deterring others that are not well-matched. The scientific literature is full of alluring words describing what comes next; entanglement, stimulus, penetration, intracellular exchange. The fungus ultimately forms an arbuscule (a tree-like structure) inside the plant root cells, specifically for the exchange of (nutrient-rich) fluids.' (A beautiful quote from mycologist Merlin Sheldrake, sourced through US organisation 'Real Organic'>) This week, after the soaking rains, I’ve noticed mushrooms and toadstools popping up in lawn areas in the town where I live. The exotic grass around these fungi is greener and at least 20% taller than the grass in nearby areas without fungi. This is a good example of a symbiotic relationship, where both the grass and the fungi are benefiting from growing together. The microbes associated with plants fall into five broad categories; the 'sexy' mycorrhizal fungi; the 'cocktail' of microbes that make up the microbiome of plants; nitrogen converting rhizobium bacteria; the 'harmful' parasitic fungi; and the 'soil building' saprophytic fungi.
This blog is about the microbes in categories 1,2 & 3, that are important to all living plants. Mycorrhizal fungi An estimated 90% of Australian plant species have a positive association with mycorrhizal fungi that live on the roots of plants. They combine in a very intimate relationship where both the plant and the fungi need each other to live well. There are usually several hundred species of mycorrhizal fungi in a few hectares of remnant herb-land, grassland, woodland, or forest. Walking through these remnant areas, you will have noticed the many colours and shapes of fungi pushing through the leaf litter. These are the fruiting bodies of various mycorrhizal fungi. Just as the fruit on a fruit tree is only a small part of the whole tree, what we see decorating the forest floor is just a small part of an immense network of root-like mycelium growing deep under the soil surface. These mycelia literally feed the tree with nutrients such as nitrogen, phosphorus and many of the minerals they need and in return plants feed the fungi with the starches and sugars it makes through photosynthesis. Since only 10% of mycorrhizal fungi produce fruiting bodies that pop up in natural places, most of the fungi that live in the soil are invisible to us. They are either too small to see or they form ‘fruit’ under the soil, known as truffles. Mycorrhizal fungi and the truffle ‘junkies’. Thousands of plants, ranging from tiny orchids to huge eucalyptus species, benefit from this symbiotic relationship with fungi. In a Western Australian study, 500 different species of mycorrhizal fungi were identified in small patches of remnant bush. In a healthy forest or woodland system, these beneficial fungi are spread around by the scratching and digging of small marsupials like Bettongs and Potoroos. These small kangaroos complement their diets by eating the fruit of fungi, particularly the truffles. It has been shown that forest and woodland plants are healthier and more diverse where these small fungi-eating marsupials still survive to enhance these ecosystems. Fungi loving marsupials will play an important role in keeping remnants and new biodiversity plantings healthy in the future. Once our most common kangaroos, they have become either threatened or extinct in most of mainland Australia. And yes, loss of their protected habitat at ground level has contributed to this crisis, but foxes and feral cats are their biggest threat. Boot camp for Burrowing Bettongs Protecting fungi spreading marsupials from predators like foxes and cats is a significant challenge that is generating some creative solutions. Predator-proof fencing has been around for decades, and it is very effective, though its high cost is often prohibitive. ($50,000/km in 2019) In the Sturt National Park, NSW, Ecologist Rebecca West is part of a team that has been training Burrowing Bettongs to avoid predators, and they’re getting results. Their most effective training method they refer to as ‘boot-camp for bettongs’. It sounds brutal to release a few feral cats into a 26 square kilometre fenced enclosure where the bettongs are living, but Rebecca and her team have found that they soon learn to avoid the cats. At first, the bettongs are naïve about the danger, but when they witness a bettong being killed and eaten, they quickly learn that cats are dangerous and that it’s smart to keep a safe distance. There is still a lot more to learn about designing the best boot camp for bettongs, but their initial trials are very encouraging. Discover more about Victoria's Eastern Bettongs in a charming story that brings you the facts in an entertaining way (7-minute read); Eastern Bettongs - 'truffle junkies or ecosystem engineers'. Plants have a microbiome. In the last decade, doctors have been emphasising the vital importance of the human microbiome to our health. These are the trillions of microscopic bacteria, viruses and fungi that live in our gut, on our skin, in our hair and in just about every part of the human body. In fact, more than half of the cells in our bodies are made up of these friendly, peace-loving, passengers that come along for the ride from the day we are born. Just as vital to plant health is their microbiome. Millions of microscopic bacteria and fungi live inside plants; their roots, stems, leaves, flowers and seed. These microbes are so important to a plant’s long-term health that they release specialised chemicals from their roots to invite them in. This cocktail of microbes is passed on to the next generation through a plant’s seed. So, a seed holds much more than the genetics of its parents, it also carries its parent’s microbiome. These specialist microbes are released when the seed germinates, and they enter its developing root system and start spreading throughout the plant. Dr Christine Jones, an expert in plant microbiology, puts it this way: “We now know that a seed has a core microbiome consisting of thousands of species of bacteria, archaea, fungi, and even some protists. The microbes in seeds are located inside the seed coat and surrounding the embryo. As the seed begins to germinate, they move into the radicle (primary root). Once the primary root has emerged, the first shoots appear. These too are colonised by microbes originating from the seed. As the plant grows, the core microbiome moves into the stems, leaves, flowers, fruits and eventually back into the seeds for the next generation." Remarkably, researchers have also shown that microbes from strong and healthy plants will move through the soil and into weaker neighbouring plants. They exchange their microbiome with other plants to help them through stressful times, however they’re quite fussy about which plants they help. They prefer to share their unique bacteria and fungi with plants from other plant families. Just as we benefit from living in human communities with wide-ranging skills and interests, plant communities that have evolved together as a diverse group benefit from this diversity. They try and maintain a variety of plant families in their communities by supporting struggling plants through tough times. Because of this constant sharing of fungi and bacteria, plants that live in a diverse plant community have more diverse microbiomes living in all of their plant parts. These richer microbiomes and the benefits that they provide are passed on to the next generation of plants in their seed. Christine Jones explains; “Microbes that begin in the seed are associated with plants through all stages of their growth and development. They are significant for nutrient acquisition and the production of plant-beneficial secondary metabolites that enhance tolerance to pests, disease and abiotic stresses such as contaminated soils or drought.” With revegetation works, Christine recommends including a minimum of 4 plant families to maximise the benefits of sharing and developing a more diverse microbiome. The flip side of this process is that plants from a depleted plant community will produce seeds with a depleted microbiome and a depleted ability to cope with stresses. Restoring the microbes The long-term survival of newly planted herb-lands, grasslands, woodlands, and forests will very likely depend on the presence of a collection of many types of mycorrhizal fungi and diverse plant microbiomes. Research in Western Australia and New South Wales has found that diverse fungal populations do not re-establish naturally in newly planted indigenous plantations. This is likely a reflection of the significant changes to soil chemistry after decades of grazing and cropping practices. The absence of the original mix of native plants has also depleted the soil of its associated mycorrhizae. The microbiomes in present-day native seed would also be depleted through the loss of so many important associations; plant to plant, plant to microbe, microbe to microbe. 'Though mycorrhizae are incredibly common (and functionally important) to land plants, they are in rapid decline. We are farming in ways that destroy these interactions, and we are now farming on half of the world’s land. Fertilizers, herbicides, and pesticides not only harm mycorrhizae, but they interfere with a plant's ability to form these relationships'. (Mycologist, Merlin Sheldrake) Creating links for soil microbes Creating links between patches of remnant bush by planting corridors of indigenous plants has the exciting potential to restore much of the lost mycorrhizal fungi. Remnants on roadsides and rivers and creeks, remnant patches on farms, small and large public reserves are all home to a diverse mix of an extraordinary variety of fungi and bacteria that once inhabited our entire Australian landscape. Planting a diverse mix of indigenous plants in an area that is linked to remnants, will modify the soil chemistry and microclimate through shade, wind shelter, the action and exudates from roots, the build-up of leaf litter, and the influence of the varieties of insects and birds that they attract. If we give the soil fungi avenues to spread, they are likely to use them, just as they have done for millennia, particularly when the soil environment begins to restore to its former character. Microorganisms have very effective airborne methods of spreading their spores and if we provide them with a suitable growing environment, they will surely adopt their new homes and flourish. An important part of change to soils will be the lowering of Nitrogen and Phosphorus to pre-European levels. Research has clearly shown that elevated soil Phosphorus suppresses mycorrhizal activity. Biostimulants. Biodynamic farmers inoculate their cropping and grazing paddocks with a dilute preparation called '500' which is made from aged cow manure. This is sprayed on cloudy days or at night to allow the microorganisms in the 500 to establish before sunshine makes contact with the soil and kills any microbes and spores that are still exposed. Organic growers inoculate seed with bio-stimulants sprayed onto dry seed before sowing. These can be made by diluting vermi-liquid to produce worm tea, or by soaking mature compost and adding water to make a compost tea. These liquids are rich in a diverse mix of microbes that benefit growing plants. Rhizobium bacteria. Another group of microorganisms that are important to plants are Rhizobium bacteria. These bacteria absorb atmospheric nitrogen and enable the legume plant families to absorb nitrogen through their roots. The families that directly benefit from this relationship include members of the Mimosaceae (e.g. wattles) and Caesalpiniaceae (e.g. cassias) and Fabaceae (e.g. davesia, dillwynia, indigophora, kennedia). The rhizobium bacteria live in nodules, which look like tiny potatoes, attached to the outside of the plant’s roots. Plants from these families can be successfully inoculated with rhizobium bacteria in the nursery before planting in the field. This is done by crushing nodules collected from seedling plants of the same species, (the nodules contain thousands of rhizobia) and adding the juice to water in a watering-can which is then watered over seedling trays when the seed is germinating. The rhizobia attach to the roots of the developing plants and support more vigorous growth when they are planted in soil. Other plant species growing nearby also benefit from the extra nitrogen that is added to the soil by these native legume plants. The microbial necromass - the largest land storage of carbon Deep under the soil, where oxygen is in short supply, there is an important though little known storage of carbon. In fact, it is where most organic soil carbon is stored more or less permanently. This makes it critically importance for carbon sequestration. It has been described as the largest store of carbon on land. At these deeper levels in the soil, it is efficiently recycled and contributes to the growth of the overall microbial biomass. It can provide up to 80% of the soil's organic matter. The microbial necromass is the accumulated remains of dead microbial cells and root cell fragments. It is permanent in the soil because the low levels of oxygen at deeper levels protect it from microbial decomposition. Necromass residues include dead microbe cells and their hyphae, fragments of cell walls plus the sugars, proteins, enzymes and DNA associated with microbial life. Land managers can increase soil carbon by optimizing necromass formation and by making it a critical component of efforts to minimise the effects of climate change. Sadly, they were toxic Yellow-stainers. I did get excited when I saw the enticing fairy-rings of mushrooms growing on roadside verges, but sadly it seems that good mushrooms are hard to find these days. On closer inspection, they turned out to be the toxic 'Yellow-stainers.’ Though it seems that the various exotic grasses growing with them didn’t find them toxic and actually benefit from being up close and cuddly. I'll take some solace though from knowing that the fresh lettuce and parsley that I put in my salad is full of the living microorganisms that make up the microbiomes of these plants. No doubt they will add diversity to my own flourishing gut flora and support my immunity in these covid times. To read more on fungi, how and where they grow, try the Australian National Botanic Gardens site. https://www.anbg.gov.au/fungi/what-is-fungus.html Also, the Interactive catalogue of Australian Fungi has some excellent photos. https://www.inaturalist.org/projects/fungimap-australia Current research into life in our soils -
You can be a citizen scientist and play a part, To care for our soils, we need to know more about them. While we know the life in our soils is in trouble, we need to know more. One important finding from the State of the Environment report was the need for more data on the biology of our soil to aid sustainable land use. Why? To date, most of our understanding of how farming impacts soil fungal diversity is based on overseas research. Despite the ecological importance of microbiota and their potential to accelerate sustainable food production, we still don’t have a clear picture of what mycorrhizal fungi live in Australia. To overcome this challenge, the Australian Research Council have launched 'Dig Up Dirt', a new nationwide research project designed to take stock of our beneficial soil fungi. Farmers, land managers and citizen scientists can send in soil samples so that Australia’s networks of soil fungi can be mapped. The data collected will also be fed into the international database - map fungi globally. This is a long-overdue step towards understanding soil fungi and conserving the life below our feet. Recapping the benefits of planting locals Indigenous plants are well adapted to the unique climate and soil of their local environment. The local insects, birds, and marsupials know and rely on the food and shelter that these very specialised plants provide. Imagine that a new supermarket chain has bought out your familiar corner store, and now it sells only brands you've never heard of and there's worse, the new supermarket only opens at inconvenient times. In the same way, local wildlife have evolved with the local plants and know their cycles, they know what the nectar/pollen tastes like and when it becomes available. They know where to find insects under the bark and which bark to use to build nests. Some wildlife may adapt quite well to the new plants in our gardens, but they may not be as healthy as they would be feeding on the indigenous plants that they have evolved with for millennia. Why plant wattles Wattles are important plants in most ecosystems because of the benefits they bring to other plants and to local wildlife. In nature, it’s common to see four or more wattle species in a wild ecosystem, ranging from the taller understorey plants down to the bushy shrub-layer wattles that I’d like to talk about today. Many of the shrub-sized wattles that are found in the Geelong region are rarely planted in gardens, yet they are a real asset in urban ecosystems. Not only are wattles an important source of food for wildlife, but they also add plant diversity, restore nitrogen to garden soils, add vibrant colour when they flower, and they’re quick growing, which makes a young garden look more grown-up. They are also quite long-living (15-20 years) and very competitive Planting small wattles under tall/mature trees The competitive nature of wattles is legendary. Many species of wattle evolved as pioneer plants that pave the way for other vegetation that needs shelter. They also compete well with existing trees. Two small bushy wattles that will fill in bare spaces and provide the very important shrub layer under mature trees are the delightful spring-flowering Gold-dust Wattle, A. acinaceae; which grows to 1 m tall, and the Myrtle Wattle, A. myrtifolia; with its distinctive red branching and red stems. It will reach a height of 2 meters. The Myrtle Wattle will brighten up the garden in mid-winter with its bright yellow pompom flower clusters. Getting plants started in dry areas under mature trees:
The benefits of providing a bushy habitat Their bushy form is very important if you want to attract small birds. If you want to bring Superb Fairy Wrens into your garden within the first few years of planting, include a tight clump of bushy wattles. For example, in the same space that you might plant a shrubby grevillea, plant three bushy wattles. Their interlocking branches will provide important protection from the neighbours’ cat that’s out prowling at night. If you want to provide super-safe accommodation for small birds, choose prickly wattles like the Hedge Wattle, A. paradoxa; or Prickly Moses, A. verticillata. The Hedge Wattle has superb bright yellow pompom flowers in spring that will brighten up any dark corner in the garden. Its extraordinary beauty is the paradox as it contrasts with the sharp cat-deterring spines along its branches and stems. A line of these shrubs planted 2 m apart will turn heads, and not just the fairy-wrens, when they’re in flower. I was interested to learn from Dr. John Morgan from Latrobe University that the common taller form of Hedge Wattle was introduced into Victoria from Kangaroo Island in the early 1900s to create stock-proof hedges. The form that is indigenous to Victoria is smaller (1-2 m) and less invasive. Prickly Moses is often found on waterways and will tolerate damper soil conditions than the Hedge Wattle. It can grow up to 4 m and its large pompom flowers from winter to spring are a refreshing pale yellow. The prickly part of this bush is its dark green leaves that taper to a point. Tough and sweet-smelling Some botanical names focus on an important feature of a plant that helps with its identification. For example, a beautiful shrubby wattle that is found throughout southern Victoria, as well as along the east coast, is the Sweet-scented Wattle, A. suaveolens which is the Latin word for sweet-smelling. This bushy sprawling wattle will grow to a height of 2 m and has delightful honey-scented creamy flower heads from June, continuing through the winter. It's one of the earliest wattles to flower. Like the smaller shrub wattles that compete well, the Sweet-scented Wattle will do the hard work under mature trees, fill up those empty spaces, and provide very useful wind shelter. Like all hardy plants that are planted in dry competitive environments, the Sweet-scented Wattle will need a little more effort to plant as described earlier, but the extra time spent will be well rewarded. Taller shrub wattles that will also perform well in these tough conditions are the Hop Wattle, A. stricta and the Varnish Wattle, A. verniciflua. Both will grow to around 3 m tall and both will provide robust shelter in windy, exposed positions. Both the Hop Wattle and the Varnish Wattle will also make a statement as single specimens in a small garden or as a natural-looking clump planted for wind shelter under mature trees. Both flower in spring, providing a welcome splash of refreshing yellow in the garden or plantation. The varnish wattle has particularly attractive small glossy leaves that give it a year-round appeal to gardeners. Food plants Two small bushy wattles that literally bring to the table something special are the Wirilda/Swamp Wattle, A retinodes; and the Coast Wattle, A. sophorae. Both are grown commercially for their edible seeds that are roasted and used for nutty food flavouring and a coffee additive. Click here to read about a commercial grower near Port Fairy. Both wattles will grow in tough garden environments and are well adapted to front-line coastal planting. Though, be cautious if you are planting A. sophorae because it is known for its 'weediness' along coastal fringes where it can spread and take over, smothering smaller indigenous plants. Both species display vivid yellow pompom flowers in spring. To make up the ten small wattles I have included a beautiful tough ground cover wattle from west of Geelong, The Thin-leaf Wattle, A. aculeatissima. This is an attractive, extremely hardy plant for rockeries or hot, exposed dry garden beds. This beautiful wattle will provide important shelter and a safe haven for skinks like the iconic Blue-tongue, as well as small birds. Its narrow leaves are a little prickly because of their pointed tip, which makes them an important habitat plant for all the small ground-living fauna that we want to attract to our gardens. Maintenance To keep small wattles looking fresh and attractive, chop them back every year or two after flowering, (or the following autumn if you plan to collect seed), with the hedge trimmers, by cutting the growing tips. This process of tip pruning not only makes the wattles bushier by increasing lateral growth, but also encourages them to flower more prolifically. Your clippings can be allowed to fall onto the garden bed as a woody mulch to suppress weeds. For prickly wattles, slide a tarpaulin under the plant before clipping to remove the thorny clippings that will make hand weeding unpleasant. These prickly clippings can be laid around tender shrubs to protect them from rabbits and hares. Avoid pruning wattles too hard, as it can cause them to die back. A rule of thumb is to avoid cutting stems that are larger than pencil thickness. Propagation Acacias are easily propagated from seed. To read more about this process and how to inoculate young plants to improve their health and vigour click here. Next month. Mycorrhizal fungi – the missing link in revegetation |
Stephen Murphy is an author, an ecologist and a nurseryman. He has been a designer of natural landscapes for over 30 years. He loves the bush, supports Landcare and is a volunteer helping to conserve local reserves. |