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Producing seed for native grassland restoration in a containerised Seed Production Area by John Delpratt  Guest blogger John Delpratt is an Honorary Fellow with the University of Melbourne and was a lecturer in plant production and seed technology at the University’s Burnley campus for 25 years. John has worked on native grassland conservation with an initial focus on cultivation and seed production systems for grassland forbs. With Dr Paul Gibson-Roy he has played a key role in the reconstruction of diverse native grassland communities by direct sowing grassland seed grown by volunteers in seed production areas around Victoria. John has generously offered to share with us his depth of knowledge on how large volumes of native grassland seed is produced and harvested for these impressive restoration projects.  A restored indigenous grassland, Glenelg H’way, Wickliffe. A reliable source of seed A reliable source of good quality and genetically appropriate seed is an important first requirement for restoring our wonderful and diverse temperate native grasslands and grassy understorey plant communities (Images 1, 2 & 3 below). With several hundred species of grasses, grass-like species (e.g. Lomandra species), colourful forbs and small shrubs comprising natural temperate grassy communities, and only a few species available commercially as seed, the grassland restorationist is left with three choices:
Collecting from local remnants requires careful adherence to permit conditions and a sound knowledge of the target species. Many remnants support an impressive range of look-alike introduced species. Also, good seasonal conditions and a number of site visits will be needed to capture the quantity of seed and diversity of species needed to build a functional and satisfying grassland. This leaves the third option; grow your own – the topic of this article and possibly the most fun! Please click on the images below to enlarge and read the caption Developing a seed production area (SPA) Purpose To grow your own seed as a cost-effective (but labour-intensive!) way to acquire sufficient quantities of good quality seed from a diverse range of species. Initial seed sources As already mentioned, many native grassland species are not readily available through commercial sources. Depending on your objectives and resources, you may be able to collect small, representative samples of target species under permit from local remnants. To grow the required transplants to start a SPA requires very little seed in most cases. To capture appropriate genetic diversity, small samples of seed should be harvested from numerous plants. For longer-flowering species, two or more harvests throughout the season should increase genetic diversity in your production crops. In recent years, geneticists have recommended that for widespread species, collecting from several populations is preferrable to growing from only one source. It can be difficult to discover the full history of purchased transplants. You can manage this by collecting your own seed. However, if good quality, locally-sourced tube stock is available it may be better to proceed with your SPA plan, rather than be distracted by the detail. Grow or purchase many (say 50 or more) small plants per species in preference to a few larger plants. In cultivation, most native grasses and forbs will grow at high densities and produce seed in their first year. Deciding to produce ‘climate ready’ seed can add an interesting layer of complexity. This usually involves sourcing a percentage of your seed (or transplants) from populations some distance from where you plan to restore grassland. For south-eastern Australia, this usually means sourcing some of your planting from warmer and dryer locations.  Image 4. A SPA operated by the Woorndoo Chatsworth Landcare Group to produce seed for their direct-sown native grassland restoration projects. Plants are grown in polystyrene boxes and irrigated with two microsprays per box. How much space do you need? The design, size and species diversity of your SPA will depend on its purpose, and the scale of your planned works. A couple of initial considerations are discussed below;
2. Are you planning to grow your seed production crops in field beds or in containers? If you are aiming to grow large quantities of native grasses, field beds may be the most affordable option. However, most field sites have a seedbank of competitive species that will quickly become contaminants in your harvested seed. Therefore, field crops require special expertise and commitment that are beyond the scope of this article, which will focus on above-ground, containerised seed production areas (SPAs).  Image 5. Burnley SPA, the production area for many of the forbs direct-sown at Gatehouse St. (image above right). Building and managing a containerised SPA One of the great advantages of a containerised SPA is that it can be established anywhere you have access to a bit of space, water, adequate sunlight and enough enthusiastic labour. If planning to establish a large area of grassy vegetation, the dominant grass species will usually be sourced from a commercial grower or from local field harvesting. Therefore, although an above-ground SPA can be built at any scale, they usually focus on species that add diversity and colour to an otherwise grass-dominated plant community. When designing a SPA, I strongly recommend that the plants be grown at around waist height. Although benches or other forms of support for your containers will add to the initial investment, ease of access to the crop will pay huge dividends in increased ease of maintenance operations and volunteer/staff comfort and enthusiasm (Images 4 & 5). Growing medium Any weed-free container medium that supports healthy plant growth (commercial or home-made) can be used. Long-term, controlled-release fertilisers will simplify the plants’ nutritional requirements. Re-apply annually. In grassland species, I’ve seldom seen adverse responses to phosphorus from standard N:P:K fertilisers (with Brunonia australis a possible exception). But if in doubt, use a low-phosphorus ‘natives’ product. Containers For relatively small-scale SPAs, polystyrene vegetable boxes are a light-weight, relatively durable container. We line the base of these boxes with a layer of geofabric to reduce the rate of drainage of irrigation water and to retain moisture below the growing medium. They can often be sourced for free but consistent dimensions can aid management. New boxes can be bought for a relatively small outlay. With minimal handling, the boxes can last for at least 5 years, although over time they become increasingly brittle and shed fine dust as they degrade. A single polystyrene vegetable box, filled with moist organic growing medium and plants, can be carried by one person (although, given the state of my ageing back, sharing the load may be better advice). If you wish to avoid polystyrene, the choice of container is limited only by the practicalities of your site, your construction skills, your budget and your imagination. The basic requirements are that the container can hold an adequate depth of growing medium (say, at least 200 mm), drains well and can be filled, planted, irrigated, maintained, harvested, emptied and re-planted or disposed of conveniently. Irrigation As a general rule, irrigation should be applied at the base of the plants (or below the plants if using a wicking bed or hydroponic-style irrigation system) to avoid constant wetting of flowers and developing seed (see Image 4). Some species are able to produce good quantities of seed under overhead irrigation (e.g. lilies). However, pollination, fertilisation and seed maturation in the dense heads of daisies and a number of other species can be inhibited if regularly saturated. Some form of drip or micro-spray irrigation delivers water directly to the growing medium surface. In a standard polystyrene vegetable box, this can be achieved with two outlets per box. Programable controllers allow for flexibility in the frequency and duration of irrigation as species and seasonal requirements vary. If growing in easily-transportable containers or where a dual system of overhead and drip irrigation is feasible, a further option is to grow under overhead irrigation for most of the year and move to drip irrigation from flowering through to seed harvest. Irrigation extends the reproductive period for many species and may allow for a second harvest period after an autumn flowering. However, some tuberous species may benefit from reduced irrigation during their dormant period in summer. Images below of the SPA at Burnley campus provided by Fiona Love from her recent visit. Click on the images to enlarge the 'weeping' drippers used to water plants.  Image 6. The stoloniferous Prickfoot (Eryngium vesiculosum) is one of several species grown in large tubs at WCLG’s Chatsworth SPA. This allows for both seed production and the harvesting of vegetative pieces for supplementary tube stock production or direct planting into field sites. Planting Planting tube stock to establish your SPA means that you can control the number and density of productive plants. Most herbaceous grassland plants can be grown to maturity at high densities. While greater numbers increase the cost of planting stock, they reduce the number of containers needed to grow the desired population of a given species. Also, it ensures you are harvesting from many small plants, rather than fewer larger plants. This strategy potentially increases the genetic diversity of your harvested seed and reduces the risk that most of your seed is harvested from fewer large plants that happen to be suited to your cultivation system. When growing in a standard polystyrene vegetable box, I usually plant from 11 to 16 plants per box (+/- 5 cm between plants). However, planting density can vary with the requirements of the species and the size of the planting stock. These same planting densities can be applied to other containers. Plants that expand by rhizomes or stolons (e.g Goodenia pinnatifida; Eryngium vesiculosum; Glycine latrobeana) are better suited to containers with a larger surface area such as raised garden beds, or similar. An added advantage is that such crops can be used for both seed production and for vegetative off-sets, cuttings or plugs. These can be used for additional tube stock propagation for supplementary plantings (Image 6 above).  To give easier access for harvest, species that produce long stems (e.g. Kennedia prostrata; Convolvulus angustissimus; Glycine clandestina) are best grown either up a trellis or where they can trail downwards. Image 7 at right is from the Burnley SPA. The trellis allows for the upward growth of Glycine clandestina. The Kennedia prostrata can spill over its boxes towards the ground. Both arrangements allow for more productive plants and easier access to the numerous seed pods.  Image 8. Murnong; Yam Daisy (Microseris walteri) in individual containers being packed into a modified box system. Once installed, the tubes were covered with additional growing medium. Irrigation water moistens the geofabric and growing medium, ensuring each plant has access to sufficient water. After a season or more of seed production, the tube stock should be available for sale or field planting. Another modification I have been trying with some success is to leave the SPA plants in a container and pack them into a box that has geofabric and a layer (say 2cm) of growing medium in its base. The bottom of each container rests on the moist growing medium allowing the plant access to irrigation water, firstly by capillary action and later as its roots expand out of the container drainage holes (Image 8 below). The plan is to use the plants for seed production for one or more seasons and still have them available for planting at a later time. Early indications are that this method is best suited to relatively open-growing species. The format allows for much higher densities because each plant has access to its own water and nutrients without too much below-ground competition from its neighbours. This could prove to be a good way to grow some tuberous species such as Murnong (Microseris walteri), Milk Maids (Burchardia umbellata) and Early Nancy (Wurmbea dioica), which may establish better in the field when planted as older, more advanced stock, while harvesting seed in the meantime. However, densely-growing plants (e.g. Linum marginale, Leptorhynchos squamatus and many others) tend to experience too much above-ground competition at these higher densities, leading to plant decline within the box.  The beautiful Bulbine Lily Harvesting Harvesting seed from small SPAs is usually done by hand or by using a small vacuum harvester. To capture most of the harvestable seed requires visiting the SPA every one to three days during peak production. However, some species can be harvested by cutting seed-bearing stems and allowing them to mature off the plant. Depending on the species, this means sacrificing some of the potential harvest but it requires much less labour. Bulbine Lily (Bulbine bulbosa) is a good example of a species whose stem can be harvested when the first two or three fruit are splitting. When the cut stems are kept intact in a dry environment, most already-formed fruits will mature their seeds over a few weeks. Of course, a level of experience is required to judge when best to harvest to limit the loss of mature seed that has already fallen while not sacrificing too much that fails to mature off the plant. ‘Optimum harvest time’ has been the subject of intense study for many agricultural and horticultural crops but has not been documented for most of our grassland species.  Kangaroo Grass, Themeda triandra, cleaned (in zip-lock bag) for sowing into tubes. KG florets and stems are visible in the black plastic tub Seed processing and storage When SPA seed of herbaceous grassland species is being produced for local, more-or-less immediate use for tube stock production or direct sowing, very little processing should be required. For most species, viable seed will be harvested along with a considerable volume of leaf and floral material. For direct sowing, we check the seed lot to ensure it contains filled seed, then simply add the harvested seed and trash to our diverse seed mixes. For other applications, such as tube stock propagation, more effort can be applied to processing the harvest towards purer seed lots, usually using a combination of graded sieves and, possibly, more sophisticated gravity and air separation equipment if it is available. For short term storage (e.g. one to three years, some species for much longer), well-dried seed of most species can be stored at room temperature or in a +/- 4oC cool room without a significant loss in field germination potential. Longer term seed storage is a large topic that is well-documented in seed technology literature. Conclusion
While we work towards and await the development of a viable, regionally-based seed industry producing a comprehensive suite of native grass and grassland forb seed, restoration projects large and small will continue to rely on relatively small-scale seed production for diversity in their sowings. As well as fostering and enabling local restoration projects, well-managed SPAs are a wonderful opportunity for productive and highly satisfying volunteer involvement and, as demand grows, viable regional enterprises. The more SPAs there are, the more our species knowledge and innovative production systems will develop and be shared. And, as mentioned at the start of this article, growing seed can be a lot of fun.
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 The Grey Wolf, Canis Lupus was reintroduced into Yellowstone National Park in 1995 The Grey Wolf Introduction by Stephen Murphy Many of us are familiar with the remarkable story of the Grey Wolf and Yellowstone National Park in Wyoming, U.S.A. The last wolf was killed in the park in the 1930's and this opened the way for the Yellowstone Elk to breed unchecked without its natural predator. Their grazing patterns also changed and the elk began camping over winter where it could brows on young willow, aspen and cottonwood trees. The loss of the trees then affected the life cycle of the beaver, a critical species supporting the parks riverine ecology. The shrinking biodiversity of the park was on the verge of collapse, when in 1995 a remarkably brave decision reversed this pattern of decline. A pack of wolves was released into the park as the world watched in disbelief. Nearly thirty years since their return, the wolves have brought about many unexpected benefits including the recovery of the beaver. 'Wolves are causing a trophic cascade of ecological change, including helping to increase beaver populations, bringing back aspen and other vegetation.' Adopting a similar strategy in Australia and returning our largest predator, the Dingo, Canis lupus dingo, to National parks and reserves would likely have similar benefits. A study lead by Associate Professor Mike Letnic noticed vegetation differences on either side of Australia's 5,614 km long Dingo fence. On the Dingo side there are fewer kangaroos and more small mammals because foxes and cats are controlled. This also resulted in a greater diversity of vegetation. A CSIRO study found greatly reduced populations of larger kangaroo species and feral goats, which were a major factor in landscape degradation, across large areas of Australian rangelands in Queensland and Western Australia. The study also found that cattle growers who encouraged dingoes had increased profits and no predation of calves by the Dingo. Professor Euan Richie explains the benefits of reintroducing both the dingo and the Tasmanian devil to mainland Australia in his excellent article below:  From the dingo to the Tasmanian devil - why we should be rewilding carnivores. Thank you to guest blogger Euan Ritchie who first published this great article on rewilding carnivores in The Conversation in February, 2023. Euan is Professor in Wildlife Ecology and Conservation, School of Life & Environmental Sciences at Deakin University. Reintroducing predators - do the benefits out way the risks? No matter where you live, apex predators and large carnivores inspire awe as well as instill fear. Large predators have been heavily persecuted and removed from areas where they once lived because of conflict with livestock graziers. Beyond their large teeth, sharp claws and iconic status, research is finding they are crucially important in ecosystems. So there is considerable interest in returning large carnivores to areas where they once lived, as part of a shift towards rewilding. Bringing back carnivores is not without risk, but it’s a potentially powerful conservation tool. Rewilding dingoes and Tasmanian devils in Australia could benefit many of our troubled ecosystems, by keeping herbivore numbers down, keeping feral cats and foxes fearful, and triggering a rebound in vegetation and small animal populations. Predators vs prey Predators can affect their prey’s behaviour. When prey species know a predator is around and perceive risk to their survival, they change how they behave. The landscape of fear predators create can make it harder for prey species to survive. That’s often good for ecosystems. The effect of dingoes in reducing, say, kangaroo and wallaby populations and changing their behaviour, can actually help bring back plants and smaller animals through a “trophic cascade”. For example, wolves chasing, eating and scaring deer can lead to an increase in the growth of plants, which can benefit other species. Predators also affect other predators. If humans poison, shoot, trap and exclude top predators like dingoes, smaller predators can increase in number and get bolder, in a phenomenon called mesopredator release. In California, when coyotes disappeared due to habitat destruction, populations of smaller predators such as cats grew and songbird numbers fell. How is it done? Rewilding can occur passively, by changing laws to stop the exclusion or killing of large carnivores and making areas more favourable for carnivores to live. When this happens, species often move back by themselves. Encouragingly, this is happening in many parts of the world, including a recent sighting of a wolf in Brandenburg, Germany. In other cases, rewilding may need a more active approach, such as physically moving animals to an area. The return of wolves to Yellowstone National Park and the ecological transformation that followed is a famous example of this, although in recent times the details of this story have been questioned. When does rewilding work best? Recent research shows wild-born animals fare better than captive-born animals, though the results are far from conclusive. Wild-born animals may have an edge due to their skills in hunting and defending territories critically important for survival.  Dingoes are a controversial carnivore in Australia. Pawel Papis/Shutterstock Rewilding in Australia means bringing back dingoes Once carnivores are killed or fenced off from an area, the ecosystem changes. Will we restore nature by bringing them back? Potentially – but it’s not guaranteed. Australia’s controversial canine, the dingo, is a perfect example. Aside from humans, dingoes are Australia’s only living land predator over 15 kilograms. Dingoes have a vital role in Australian ecosystems, such as keeping populations of kangaroos and emus under control. They can also take down feral goats. Their natural control of herbivores means plants can bounce back, as well as making room for smaller animals. Their effect on plant life may even affect the height and shape of sand dunes. In some parts of Australia, kangaroo populations have exploded. Land clearing for pasture favours kangaroos, as do the dams and water troughs for livestock, the killing off of dingoes and the ending of First Nations Peoples’ cultural practices and hunting. At times, these population booms have led to sudden crashes, with widespread starvation in droughts. Harvesting kangaroos is one response, but this is often controversial and unpopular. Bringing dingoes back would help reduce kangaroo numbers in a way more palatable to many people. When present, dingoes also keep a lid on our worst introduced predators, feral cats and foxes, either by eating them or forcing them to alter their behaviour. If cats and foxes have to be more careful, it may benefit their smaller prey. We could rewild dingoes very easily by removing large barriers like the dingo fence. This, of course, would trigger pushback from livestock graziers worried about attacks on their stock. It doesn’t have to be this way though. We’ve learned a lot about ways to reduce conflict between farmers and predators. It’s now entirely possible for livestock producers and top predators to coexist. Western Australian farmers are already using guardian animals such as Maremma dogs to protect livestock.  An insurance population of Tasmanian devils has been established on Maria Island. David Clode/unsplash. So should we do it?
Australia has been slow to support and attempt large carnivore rewilding. But we can learn valuable lessons from the relocation of Tasmanian devils to an offshore haven, Maria Island. Devils were introduced to safeguard the species against the severe population decline from devil facial tumour disease. These predators were not native to Maria Island, but they’ve flourished. One unexpected side effect was the devastating impact on the island’s little penguin population. Rewilding comes with risks. But it also comes with major benefits, which may help our collapsing ecosystems and threatened species. Time is short. Conservation must take calculated and informed risks to achieve better outcomes. Rewilding attempts are valuable, even when things don’t go entirely as planned. What else could we do? Discussions over the carefully planned reintroduction of Tasmanian devils to mainland Australia continue. If the devils come back to the mainland for the first time in thousands of years, they might help to manage herbivore and feral cat populations. Rewilding is not about recreating the mythical idea of wilderness. Humans have shaped ecosystems for millennia. If rewilding and ecological restoration is to succeed, communities and their values, including First Nations groups, must be involved.  A beautiful carpet of Common Riceflour, Pimelea humilis, a grassland champion. These plants are still thriving in the Point Richards Reserve, Portarlington Turning the tide - time for a grasslands revolution You’ve received a mysterious invitation from a close friend to a grassland party. ‘A what? You think – that’s quirky!' When you arrive, you’re greeted at the door by your very excited friend, who ushers you into her lounge where four other women from your preschool group are seated. You give one of them a quizzical look. She raises her shoulders as if to say, ‘search me?' Your friend claps her hands and says excitedly, “Ladies, you’re here to share in my new passion. You’re here to help me turn back the clock 180 years. You’re here to help me plant my grassy back yard into a low maintenance, wildlife friendly, carpet of beautiful, local wildflowers.” Does this gathering of young mums sound feasible to you? Could restoring indigenous grasslands in backyards capture the enthusiastic support of Australians from all walks of life? Is it possible to start a revolution that would see indigenous grassland plants return to the streets and gardens of our nation? The carbon sequestration benefits of planting millions of deep-rooted perennial plants would be reason enough to support a grassland revolution.  Hoary Sunray, Leucochrysum albicans, a grassland champion. It spreads into open areas and isn't grazed by kangaroos or wallabies If you're worried about the continuing disappearance of our grassland flora and fauna, you would probably agree that a significant challenge is to develop relatively uncomplicated methods of restoring native grasslands that can be applied on a small or a large scale. This would empower more land managers, including young mums with small backyards, to restore indigenous ecologies on a variety of Australian landscapes. It is an intriguing challenge that desperately needs some serious thought and some practical solutions. What follows in part 3 of Restoring Native Grasslands is a catalyst for discussions about how this restoration could be done. Part 1 of Restoring Native Grasslands, looked at the history of grasslands in Victoria and how our landscapes have changed since settlement in 1835. Part 2 of Restoring Native Grasslands looked at some larger-scale restoration success stories and what can be leant from them.  Bower Spinach, Tetragonia implexicoma, will smother invasive weeds and grow in dry situations under mature trees Grassland plants fight back – in a nutshell; Your mission - to plant an island of grassland plant champions and then get them through their first year.
 Native Geranium, Geranium retrorsum, is a forb with a deep succulent root system which competes well with exotic weeds. Blow by blow - in bruising detail: 1. Plant islands of indigenous plant champions. Bellarine Landcare’s Grasslands Interest Group has put together a list of very hardy local grasses, lilies and herbs that are capable of going head-to-head with weedy interlopers. (Thank you also to John Delpratt and Stuart McCallum for your contributions to the list of grassland champions) Grassland Champions list: The Grassland Champion’s list presently includes 76 species, from 50 genera, and 22 families that are found in central Victoria. This list can be extended with other hardy indigenous plants which are local to your area. When the champions begin to take control and improve the soil chemistry, other less hardy plants can be added. The list is in the form of a table that includes other useful information. Click here for the table Always include some nutrient strippers in your plant list. Nutrient stripping plants like Kangaroo Grass will help maintain lower nitrogen (N) & phosphorus (P) levels in your island planting. Plant in groups/clumps of the same species - 10 to 50 plants/clump is ideal. Plant smaller species in larger numbers so they can dominate their given area. See the champions table for the recommended spacing for each species Why plant in same species clumps? Planting in clumps looks great, is nature's way, attracts more pollinating insects and will produce more fertile seed, giving the grassland champions the greatest likelihood of spreading into surrounding areas.  Common Rice Flower, Pimelea humilis (white flowers), surviving on a weedy privately owned building block. The soil fungi needed to support this plant would still be present. 2. Choose the best place to plant the champions. Look for helpful indicators of where indigenous plants will best grow. Plant near remnant grassland plants:
Read more about identifying native grasses here Choose the best soil for native plants:
 Oxalis comes in many sizes and colours. This yellow flowering variety is probably the most common and invasive 3. Avoid planting near invasive weeds like Kikuyu, Couch, Phalaris, Paspalum and Oxalis. These are dominating and destructive perennial weeds that are best managed with an application of herbicide. Ideally follow up with a cool burn when they die and spray with herbicide again if they reshoot. Show them no mercy because they will take over the grassland and destroy all your good works. Once they invade they are much harder to control. Using this process, you will systematically eliminate difficult-to-manage weeds, though it is likely to take two growing seasons. Planting grassland plants before these tough resilient weeds are banished, will only result in disappointment. A note on spraying with glyphosate: Herbicide is a useful tool if it is used safely and intelligently. The time to spray is when the weeds look healthy and are showing strong growth up to 10cm tall. Allow more top growth before spraying deep-rooted weeds like Phalaris and Paspalum. (See pictures below). Kikuyu and Couch grasses die back naturally in winter, so spraying at this time does them no harm. It is better to spray these weeds in late spring or early summer when they are growing strongly. Oxalis is best sprayed at the beginning of its flowering cycle when the plants have just a few flowers. Spraying at this time will kill the many small bulbs (future plants) that are attached to the oxalis roots. My personal story. As an organic vegetable grower, I have tried hand-weeding these difficult weeds year after year. This involved putting the soil through a sieve to remove any potential growing shoots or bulbs which is a slow and tedious process. Yet, still the problem weeds kept coming back. I swallowed my disappointment and applied one well-timed spray with 1% glyphosate, the recommended rate for difficult-to-manage perennial weeds, and eliminated them. To put this spray-rate into perspective; 1% is equivalent to spraying 1 teaspoon of glyphosate concentrate over a 25 square meter area of perennial weeds. The remarkable environmental benefits gained from establishing 5m x 5m of healthy native grassland clearly outweighs my environmental concerns about the use of glyphosate.  Kangaroo Grass mass planted in an island planting to lower nitrogen levels. No nutrient stripping was done on this site, so more hand weeding was required. Nutrient stripping – a big blow to the weedy interlopers: Reverse fertilisation.
Burning the stubble when it dries will further lower N & P levels and adds smoke chemicals to the soil that enhance the germination of many native seeds.
 Planting scattered canopy trees will lower soil nitrogen and phosphorus levels. Photo. Deanna Duffy
Planting scattered canopy trees at a similar density to the original pre-settlement spacing will create an open grassy woodland and lower soil nutrient levels. This nutrient lowering effect has been observed to extend at least 1.5 x height of canopy trees from their trunk. Therefore trees reaching a mature height of 20 m will lower soil nutrient levels up to 30 m from the tree’s trunk. Planting nine, 20 m tall canopy trees over one hectare will eventually return the soil nutrients to a pre-settlement lower levels. (This density was calculated on an average spacing of 30 m between canopy trees). Note on planting canopy trees: Canopy trees planted in groups of 5 trees (tree spacing of 3m within these groups) has many advantages:
Planting clumps of shrubs. An alternative design is to include clumps of indigenous shrubs and understorey trees. This will diversify the sources of food and improve habitat for wildlife. To lower soil nutrient levels, the shrub-clumps and the clumps of understorey trees are spaced at 1.5 times their mature height. Therefore, a clump of twenty, 5 m tall shrubs, will lower soil nutrients 7.5 m beyond the outer edge of the clump. A clump of 10 understorey trees with a mature height of 12 m tall, will lower soil nutrients up to 18 m beyond the outside edge of the clump. Within these clumps, the plants are spaced at 2 – 3 m. In this way, a mixed shrubby woodland with grasslands in the open areas could be restored over 1ha of over multiples of 1ha.  Compost teas can be sprayed or watered-in with simple and safe gardening equipment Making compost teas. Microbe-rich inoculations have been shown to stimulate the revival of some grassland species. Microbe-rich teas can be made from worm-juice, compost or manure. A concentrated tea is made by harvesting worm juice or by placing a permeable bag (e.g. hessian) containing about 9 L (one full bucket = 9 litres) of compost or manure into a 150 L drum of water (40 gallons). (These volumes can be scaled up or down to suit the size of your project). After one week, the microbe-rich water in the drum is diluted to the colour of weak tea and sprayed over the grassland plants. This is best applied when the soil is moist, on a cool, cloudy or rainy day, in mid-spring or mid-autumn. Direct sunlight will kill the microbes in the tea. The benefits of inoculating with microbe-rich teas is discussed in; Restoring native grasslands - part 2  A cool burn will lower soil nutrients and add smoke chemicals which enhance the germination indigenous grassland plants. Photo Gib Wettenhall Spreading out from the island plantings Paul Gibson-Roy and John Delpratt noticed grassland plants spreading well beyond the edges of their restoration sites; “At all Grassy Groundcover Research Project restorations, native grasses had colonised some tens of metres beyond the boundaries of the original restoration zones and at a large number of sites, forb species had also expanded beyond the restored area” (Paul Gibson-Roy and John Delpratt. 2015. Land of Sweeping Plains. Chapters 11 & 12.). When the island planting is established, the exotic weeds growing around the fringes of the island are your next frontier to conquer. The techniques discussed under ‘Nutrient Stripping’ can be used to expand the island planting:
...the backyard planting
About two years had passed since the grassland party and Cathy was surprised at how well her family had adapted to the new backyard. Instead of a regularly mown grassy patch, it was now a accidental meadow with a mosaic of colour. Her four-year-old loved running through the wildflowers and watching the white and brown butterflies flutter into the air around her. There was something wonderful about seeing a carefree child, arms raised, eyes looking upwards, red curls twinkling in the sun, following the silent random flight of the fluttering butterflies. |
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. 
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