Bush tucker for roofs

Evolvement are working on a number of australian wild food plant species that can be grown on roofs. In our builtup environment, green spaces are hard to come by, roofs provide a perfect solution. Following our succesful implementation of a food garden on a concrete slab at Cockatoo Island (shown below) we are most interested to work on green roof design for food and pleasure.

We think we have some exciting possibilities, call us for more information on 0468 787 071.

Evolvement / Greenlook have just completed a Popup restaurant (Don Tapa) on Cockatoo Island in Sydney. Gardens are planted with Australian bushtucker plants, many species of plants that sustained the indigenous people for the past 60,000 years. Bushtucker species list below.

We have planted food crops in Boifilta self watering planters, here a rich variety of herbs and vegetables are grown for the kitchen. Lots of chillies too  for the South American cuisine. Royal Grass synthetic grass is used for play and real grass beds for looking at the sky. large trees were planted to give the restaurant a great green look. All aspects of the restaurant are transportable, including the landscaping.

The Bush Tucker plant list grown by Greenlook's own nursery are:

Bulbine Lily - Bulbine bulbosa

Murnong, Yam daisy - Microseris lanceolata

Chocolate Lilly – Dichopogon fimbriatus 

Lemon Aspen – Acronychia oblongifolia

Midjinberry – Austromyrtus tenuifolium

Mountain Pepper – Tasmannia lanceolata

Rubus  rosifolius – Native Raspberry

Native Finger Lime – Microcitrus australasica

Native Ginger – Alpina caerulea

Sandpaper Fig – Ficus coronata

Small leaved Fig – Ficus obliqua

Native Lemon Grass- Cymbopogon ambiguus

Native Guava- Eupomatia laurina

Lemon Myrtle – Backhousia citriodora

Sea Fig - Coastal Pigface - Carpobrotus glaucescens

Bunya Pines

Illawarra pines

Black Apple 

Cabbage Palm

See www.greenlook.com.au for more details.

Many thanks to our client Anatoly and Irene from FutureCities.  http://www.futurecities.com.au/ 

Biofilta for their unique vegetable wicking bed technology. www.biofilta.com.au 

Australian Native Landscapes for generous landscape supplies. www.anlscape.com.au

 

Biofilta and Urbanscape make a perfect combination for urban food production

In Oct 17 Evolvement Pty Ltd provided the installation of 2 Biofilta FOODWALL systems for The Institute of Landscape Architects International Festival in Sydney. To maximise capillary action in the Biofilta FOODWALL TM we installed Urbanscape Green Roll. The combination works a treat. Water from the Biofilta water reservoir irrigated the new vegetable and herb plantings. The Urbanscape Green Roll system also proves very successful for water holding and insulation on green roofs.

Robert Griffith CEO with Urbanscape Green Roof system media ready for installation. Urbanscape does not rot and it has a great ability for wicking from the water storage tanks to the plants.

Robert Griffith CEO with Urbanscape Green Roof system media ready for installation. Urbanscape does not rot and it has a great ability for wicking from the water storage tanks to the plants.

The Biofilta FOODWALL is an easy way to be a successful urban farmer. It is highly productive with minimal care.

The Biofilta FOODWALL is an easy way to be a successful urban farmer. It is highly productive with minimal care.

Recent project using Biofilta at the George Institute, Sydney. The system is simple and most effective. This is what the client said "Love the fact we are growing vegetables at work. Seriously impressed with the way the @Biofilta tubs work so w…

Recent project using Biofilta at the George Institute, Sydney. The system is simple and most effective. This is what the client said "Love the fact we are growing vegetables at work. Seriously impressed with the way the @Biofilta tubs work so well even in such harsh enviro."

Setting up Biofilta vegetable gardens with Urbanscape Green Roll, for the AILA conference today in Sydney. The benefit of using Urbanscape Green Roll is that it provides an excellent wicking system for Biofilta Foodwall. Here at the Future Street in Sydney we apply the technology for great results.

New Green roof research for NSW provides light weight green roof, cost effective storm water management and plant growth knowledge

Scientific testing of Knauf Insulation’s Urbanscape® Green roof products is taking place in two locations in Sydney. Knauf Insulation is a major supplier of insulation products and mineral fiber based growing media around the world. Their new Urbanscape® Green Roll growing media designed for Green Roofing and Landscaping is now available in Australia. The product is made from pure rock mineral fibres (no additives added) providing excellent water retention for different landscape applications. Offering significant improvements at a lower cost and weight than typical green roof systems.

Test panels on planting day provide information on various growing media depths, weights and Knauf Insulation products, installed and monitored by Evolvement Pty Ltd at Andreasens Green Nursery.

Test panels on planting day provide information on various growing media depths, weights and Knauf Insulation products, installed and monitored by Evolvement Pty Ltd at Andreasens Green Nursery.

A series of test plots have been installed to monitor storm water management and plant species performance. The test sites are available for inspection by prior arrangement at Andreasens Green Nursery at Kemps Creek. An additional test site is located in Berowra Sydney. Data has been recorded since April 2017, it shows important advantages for development sites and retrofitting existing roofs.

 

Roofs using Urbanscape®Green Roll provide significant stormwater control and retention. Peak discharge is greatly reduced and water exiting the system is noticeably cleaner.  Green roofs and landscapes using Urbanscape® growing media will require far less water to flourish. Plant species information is available to provide the most sustainable outcomes. Green roofs reduce energy consumption, cool cities, whilst providing sound attenuation and biodiversity habitat.

 

These test panels will enable landscape architects, architects, developers and engineers to specify green roofs in NSW for specific storm water retention. Structural engineers will know the green roof loads. Contractors will have clear instructions and training on how to install the Urbanscape® products on their projects.

 

If you submit your building details to Evolvement Pty Ltd, a comprehensive model for your development can be provided for any Australian location, showing peak discharge stormwater and energy conservation based on your roof profile and planting scheme and you can even require UHI reduction effect

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Native planting and Sedum planting trial plots at the Evolvement office site in Berowra. These plants are growing in 40mm of growing media and Urbanscape®. The saturated weights are less than 60kg per M2. Plots receive very little water and are flou…

Native planting and Sedum planting trial plots at the Evolvement office site in Berowra. These plants are growing in 40mm of growing media and Urbanscape®. The saturated weights are less than 60kg per M2. Plots receive very little water and are flourishing after on 4 months of winter. Berowra rainfall is similar to Sydney CBD

Evolvement Pty Ltd has established itself as a scientific organisation, which specializes in Green Infrastructure. Director Robert Griffith has spent the past 10 years working in various countries on green roof, water management and vertical garden projects. For further information contact Robert at rgriffi8@gmail.com, 0468 787 071 and www.evolvement.sqsp.com.au .

Best green roof so-far in terms of cost, weight and stormwater management

The Evolvement team have been conducting trials on a range of green roofs in our nursery. We are testing water management for runoff quantity and quality. The roofs provide horticultural monitoring of Australian native species and exotics suited to green roofs. Weight per M2 is another important factor we determine. Six different variations of green roof have been tested with different growing media and plants. Rainfall events and the resulting runoff data is collected and used to enhance our understanding of each system. Evolvement have worked with engineered growing media that provides both insulation and permanent growing conditions for a range of plants. 

Green roof in Bondi with native plants providing water management and energy efficiencies.

Green roof in Bondi with native plants providing water management and energy efficiencies.

Developers and architects in Australia are still hesitant to install green roofs as they are a load on the building and have potential to leak if not installed correctly. There is a general lack of understanding of how the system provides services. Compliance does however require developments to control peak discharge rates and provide energy savings. Evolvement now has relevant information on a range of systems to meet these requirements.

And THE WINNER IS! Plot number 3.

Plot number 3 weighs in at 45kg/M2. This is a fully saturated weight, few roofs will not be able to cope with this weight as a green roof system. The light weight and hence minimal materials required to provide for plantings also means considerable savings in installation and removal costs. 

Evolvement green roof test panels showing rain gauge for monitoring precipitation. In May 2017 we received heavy falls. Our best plots provided a huge reduction in runoff and water quality was excellent. Peak discharge rates were remarkably reduced.

Evolvement green roof test panels showing rain gauge for monitoring precipitation. In May 2017 we received heavy falls. Our best plots provided a huge reduction in runoff and water quality was excellent. Peak discharge rates were remarkably reduced.

Plot number 3 retains 90% of most common rainfall events. This retention rate provides the ecosystem services common in bushland or forest areas, where water is absorbed into the ground and purified before it enters creeks and rivers. 

Plot number 3 runoff is visibly clean and provides no gross pollutants and exceeds nutrient runoff requirements. We note that where only green roof soil media is used the water is visibly dirty after rain events even through a filter fabric.

Plot 2 used a quality engineered growing media and filter fabric only, this results in poor water quality and as you can see a large quantity of runoff after 25mm of rainfall.

Plot 2 used a quality engineered growing media and filter fabric only, this results in poor water quality and as you can see a large quantity of runoff after 25mm of rainfall.

Plot 3 incorporates is a synthetic growing media that is lightweight. As you can see after 25mm rain the plot only drained 250ml of clean water.

Plot 3 incorporates is a synthetic growing media that is lightweight. As you can see after 25mm rain the plot only drained 250ml of clean water.

With the correct waterproofing and the addition of a leak detection system developers and architects need not worry about their building leaking. In fact there are many studies overseas that prove that green roofs will extend the life of waterproofing almost indefinitely and increase building life generally as roof temperatures remain static. Of course this temperature reduction reduces energy consumption considerably for your building.

Evolvement can design your next green roof system and its performance. Call Robert on 0468 787 071.

Designing with plants

As a landscape designer and horticulturalist, I take pleasure in thinking through the meaning, limitations, structure, seasonality, texture, colour, and composition of plantings that I work on.

My apprenticeship at Swanes Nursery and working in their dispatch department putting on 10,s of thousand of plant labels helps me know species, as does a 35 year collection of books and visiting gardens of the world. Although I do not agree with the green thumb concept, I do think that 40+ years working with plants of the world does provide some instinctive good choices.

Natives on roofs, textures used to soften concrete.

Natives on roofs, textures used to soften concrete.

Talking generally for gardens my design objects revolve around:

  • Don’t solve problems by throwing money at it. Design by being mindful about resources. Even small plants grow quickly given the right conditions.
  • Rely on plants that evolved to deal with our land and climate and thus provide resilience and longevity. Natives are a good option.
  • Select those plants that would be suitable for a specific garden environment. An understanding of the garden aspect, hours of sun, climate, wind, rain and soils, is it indoor? These effect what you can expect to grow.
  • Develop a composition that could be reproduced in variations in other locations.
  • Aim for an end result that communicates care, value, and pride.
  • Keep the garden design simple enough so that it could be maintained without the knowledge of a expert gardener.
  • Bend some rules.
  •  
  • Why didn’t I mention colour, texture or succession? Well, they are not objectives, they are essentials.
That lush look with water

That lush look with water

With this framework in place, I could move on to the next one. Let’s call it the…

…Functional framework

Providing a shady place to sit, attracting wildlife, producing a pleasing fragrance – can help us connect with and value our leafy counterparts.

If I’m designing a green roof or vertical garden I will usually go for show, large groups of plants that can be seen for their individual colours and textures. Fine leafed plants give distance, large dark leafed plants bring the garden closer. Ecosystem services of improving water and air quality play a role in my plant choices here too.

To keep a rain garden functioning, I need to maintain the soil’s infiltration capacity – or, even better, improve it. The extensive and fibrous root systems of our native sedges do just that.

My gardens generally don’t come close to the vastness of our grassland, bushland or forests. Many trees are tall, which makes them a perfect fit for vast landscapes. To achieve a level of proportionality, I will have to rely on groundcover, a matrix of shrubs and smaller trees, species that are smaller, more compact, and a better fit for the space.

A wetland planting for water quality

A wetland planting for water quality

Still, I would like to add some structure, texture, contrast, and seasonality. Another rule bender is the addition of non-native geophytes like: Bromeliads for outstanding colour, fruits and vegetables for consumption.

Native plants have the stigma of delivering a wild and messy look. For those that like a clipped hedge this may be distressing.

And this is why colour composition, texture, and seasonality are important. They distract – or, even better – re-focus the observer’s attention. They create a new narrative that communicates care and intent, as a contrast to what is typically perceived as un-tame native plants.

While working with combinations of flower and leaf colours is interesting, what really captivates me is textures and contrasts. Yet I can’t take credit for composition, because my inspirations came from stunning scenes I observed in nature and the many great gardens I have visited around the world. I will say that with creative maintenance a native garden can look pretty smart.

Committing to a native plant pallet in a design comes with its limitations. And that, as it turns out, can be a good thing. It’s something that keeps driving the creative process. Rather than getting bogged down by what a list of natives doesn’t provide, we begin to discover and explore their unique features and elements, whether it is the eye candy part or the functional element – managing stormwater, cooling our cities and improving our health.

Using native accent plants for dramatic effect

Using native accent plants for dramatic effect

Plants make for a great restaurant business

Hi, I couldn't help but share some photos where plants are improving restaurants businesses. I took the photos on both sides of the world. One in Connecticut US and one from Sydney Australia. I will let you guess which is which, and tell me why. 

Restaurant 2 Sydney or Connecticut?

Restaurant 2 Sydney or Connecticut?

Restaurant 1 Sydney or Connecticut?

Restaurant 1 Sydney or Connecticut?

Restaurant 2 Sydney or Connecticut?

Restaurant 2 Sydney or Connecticut?

Restaurant 1 Sydney or Connecticut?

Restaurant 1 Sydney or Connecticut?

Restaurant 1 Sydney or Connecticut?

Restaurant 1 Sydney or Connecticut?

Restaurant 2 Sydney or Connecticut?

Restaurant 2 Sydney or Connecticut?

Horticultural imagination is what makes outstanding gardens

My recent trip to Singapore reminded me again what can be done with plants. In my travels around landscapes in Sydney I see mediocrity and the resulting bland landscape. We are all to often drawn to the plants we know will live with little maintenance.

Yes I know Singapore offers a unique climate where almost anything thrives, but here in NSW we can actually grow more species as we can also grow the cold climate plants.

Sure we can grow some neat clipped green hedges, then there are the pretty ugly gardens below. Even when we have more variety its pretty bland.

Above are 3 bland gardens

Designers use form, colour and texture to add interest to planting areas. Here are some better examples I have seen recently. Horticulturalists know how to make them grow well for the long run.

The colourful shots below are mostly straight from my garden in Sydney or a climate just like NSW, form and texture provide interest. Horticulture ensures they thrive.I hope you like my snaps. Robert. rob@greenlook.com.au 

You see plants can offer some great design outcomes whilst providing countless environmental benefits.

If you want to see a most outstanding garden for me, go to Gardens by the Bay in Singapore!

Evolvement provides green infrastructure training to Singapore Government and Contractors

It was a honour to share our experience with CUGE in Green infrastructure,  (green roofs, vertical gardens and water management) this week. CUGE is the Centre for Urban Greening and Environment in Singapore. A survey was carried out on what skills and knowledge government and industry required,  Robert Griffith developed a course meet these needs.

Robert Griffith showing students thermal images of green walls which are reducing energy usage.

Robert Griffith showing students thermal images of green walls which are reducing energy usage.

A class of 30 attended the 2 day course. We covered the design, installation and maintenance using a  broad range of materials and products. Over the past 10 years Evolvement have collected considerable information and experience of diffeent systems. Working with designers and installers in Germany, The Middle East, Asia, USA and Australia, we are able to share a broad range of solutions.

The hands on parts of the course and the site visits were well received. Students noted that using the products and fitting them together gave a much better understanding of how the systems work.

Each student was able to fit planters and irrigation nozzles to build a green wall.

Each student was able to fit planters and irrigation nozzles to build a green wall.

Vertical gardens visited included both thin fabric and module systems covering over 1000M2 in size. We brought  along the installers and maintenance staff to talk us through the whole process of how the projects were completed.

We meet the installation team and maintenance crew for this Patrick Blanc wall at 6 Battery Road. There are over 100 species of plants on this indoor vertical garden.

We meet the installation team and maintenance crew for this Patrick Blanc wall at 6 Battery Road. There are over 100 species of plants on this indoor vertical garden.

Here at ITE Central the chaps from Elmich gave us a good understanding of how this 800+m2 wall was built and the difficulties encountered.

Here at ITE Central the chaps from Elmich gave us a good understanding of how this 800+m2 wall was built and the difficulties encountered.

It was interesting to note that many students commented on how "green" in Singapore needs to be lush to satisfy people's tastes. This means that the light weight extensive roofs are less common, despite their ability to provide cost effective environmental benefits . Another reason is that the sedum species commonly used in cooler climates on light weight roofs are not suitable in the tropics. 

Students were pushed to think about where they see there preferred position in the industry and projects. Some commented on the benefits of learning about water management. Each person calculated a water balance for their favourite project during class. Others were more interested in the maintenance angles, they learnt on the tour from the staff that do the work.

I hope to be running further courses with CUGE aimed at specific topics with technical hands on components for the

  • Ecology of green infrastructure,
  • Extensive roofs
  • Zero net water design 
  • Urban farming

On further courses we will discuss the different techniques and materials required for each of these greening applications. 

6. Important tips for greening your home or business space

1. For hot aspect gardens use succulents. Sedums provide a huge variety in as vertical garden or as ground covers. Ripsalis species are well suited as they often grow in the air and look dramatic in form, they are great for indoor and outdoor situations. Here are a few succulents growing in a recycled tyre green wall built by Evolvement Pty Ltd.

 

2. Indoor plants may need artificial lighting. Plants require a specific spectrum. Metal Halide lights typically are the best for this although use a lot of energy. New LED lights are available but expensive. Locating your green walls near windows will reduce energy use.

 

3. Where turf wont grow due to shade, wear or dogs, synthetic turfs are available that are luxurious and natural looking, see more (www.greenlook.com.au)

 

4. Terrific hardy plants you can't go wrong with for indoors include Pothos (Epipremnum "Aurea") , Spathiphyllum, Spider plant (Chlorophytim 'Variegata'), always include these in your mix with some more exotic species. These species are good in low light areas. 

 

5. Green roofs can grow as much food as you need. Chilies, herbs, greens are very productive. Local grown plants are now a major feature of restaurants and bars around the world. They are both attractive and ideal for "good for you" and "low energy" food marketing.

 

6. Pots and steel green wall divider can be great for growing lush plants on hard terrace paving surfaces.

A remarkable female Scientist Dr Ilma Pideon 1915-2006

Having a passion for ecology on green roofs I came across a remarkable female scientist. Her name was Dr Ilma M. Pideon, maiden name Ima Brewer. Ima's work in the 1930's has helped me understand the processes of plant succession on Sydney's rock landscape.

View from the clifftops down to the Hawkesbury River

View from the clifftops down to the Hawkesbury River

lma Brewer was Lecturer in Botany/Biology, University of Sydney 1963-1970 and Senior Lecturer in Biological Sciences 1970-1978. She developed new methods of teaching based on the recognition that a student learnt more by working at his/her own pace and instructing him/her self. Her findings were published as a book, "Learning More and Teaching Less".

http://trove.nla.gov.au/people/1094661?c=people 

In 1938 she wrote a paper on Plant Succession on the Hawkesbury Sandstone. Some of her observations relating to my interest in green roofs and these plants are below:

Micromyrtis blakleyi, Baekea brevifolia amongst native grasses and moss on 25mm soil depth.

Micromyrtis blakleyi, Baekea brevifolia amongst native grasses and moss on 25mm soil depth.

"The sclerophyllous vegetation of the Hawkesbury Sand- stone is characterised by hard, tough, dry leaves, and has developed under conditions of bright sunlight, exposure and ready drainage through a shallow soil of poor water-retaining capacity."

"Deficient drainage, induced by a series of comparatively level areas, results in the formation of swamps which are quite common on the surface of the plateau, and are less frequently represented as "hanging swamps" in the upper parts of valleys."

"The surface of the plateau is exposed to intense sunlight and strong  wind action"

Close up of the vegetation

Close up of the vegetation

In the Hawkesbury sandstone the rock is normally extremely deficient in water... she discusses this low water condition as as the Xeric Lithosere. Algae, crustaceous lichens, foliose lichens, xeric mosses and fruticose lichens,  hemicryptophytes and shrubs form communities which comprise the initial phases of the xeric lithosere. Lithosere is a succession initiated on bare rock. Xeric lithosere refers to dry rock succession.

My favourite plant Myromyrtus blakelyi

My favourite plant Myromyrtus blakelyi

A green wall for large development sites

Well you could call it an embankment but in this case I am going to explain how to get it to grow a lush green wall of plants. It is also a green wall that can save a lot of money and energy on projects where excess fill and spoil needs to be removed. Generally this type of wall will require a fair amount of horizontal space, around 1.5 metres for every metre you want to go high.

Your embankment will cool your development, provide a spectacular feature sequester carbon, and save the expensive removal of spoil. Whilst I'm at it, why not include a paths for exercise and play areas for children. Everyone loves a hill to climb with views.

If is is built well using horticultural techniques it will be beautiful. If not built correctly it may just grow weeds or even worse nothing!

Below is some photos of the green wall so you can get an idea of what I mean. Lets call it "Andrews Farm Green Wall". Below I will provide the specification for this green wall. 

Native plants on a successful embankement. In this case the plants were mostly self seeded. Yearly slashing keeps plants looking young and lush.

Native plants on a successful embankement. In this case the plants were mostly self seeded. Yearly slashing keeps plants looking young and lush.

Two projects I have worked on as green structures are 1. at the Southern end of the M7 Tollway in Sydney and it is called the Pyramid and 2. Sydney Olympic site called Kronos Hill. Both projects required a lot of fill and were great places to put a vast quantities of spoil that was not required on the projects. 

M7 Pyramid, this mound was a place for a huge amount of excess fill and is grassed.

M7 Pyramid, this mound was a place for a huge amount of excess fill and is grassed.

Kronos Hill Sydney Olympic site has a track to the top and native plant cover.

Now back to Andrews Farm Green Wall, its 6 metre high and has a base of 8 metres deep. So around a 30 degree angle. In this case it only has one side as it is built against a cliff.

A specification to build such a wall would include the following layers.

A) The first layer and up to 800mm from the surface. Materials could be clay, sand, soil, rock, waste concrete, bitumen, even in large pieces. Is would be good to mix the components especially if there is some clay or soil. Water holding capacity, drainage and porosity is beneficial.

B) Clean fill suitable for plant growth. This layer will be between layer A above and to within 400mm of the surface of your green wall. Water holding capacity, drainage and porosity is essential. A soil test will be required to ensure it is has suitable water holding capacity, drainage and porosity. Send me a sample and I will do an analysis for you. T: :61 468 787 071.

C) Mix 200mm of B) above and D) below.

D) Good growing soil.  Send me a sample and I will do an analysis for you. T: :61 468 787 071.

Andrews Green Wall sketch.

Andrews Green Wall sketch.

Mulching with organic or gravel mulches will help reduce weeds.

Erosion mesh may be required for erosion control, a biodegradable one can be suitable until plants establish.

Temporary or permanent irrigation may be required.

Planting layout and species will be provided by a horticulturalist. Seeds and tubestock can be used to make this quite inexpensive. Around 4 plants per M2 will suffice.

Engineering of mound to avoid erosion will depend on components A, B, C and D above.

Let me know if you have such a project, I would be please to assist you. Contact 0468 787 071 or rob@greenlook.com.au. 

 

Water quality using art for people and biodiversity

Recently I went past one of the projects I built in Sydney back in 1999. It is around the Duck Pond in Sydney's Centennial Park. This and other ponds here are designed to clean stormwater from one of Sydney's most populated suburbs, close to the Central Business District.

My team and I provided habitat for the rich biodiversity found in the park both aquatic and terrestrial. I was wondering how the job was holding up after 18 years. Well I was surprised that there had been little change, so we must have done a good job. Actually all the materials for this project were recycled so they had a longer history than that. 

Interpretive signage was aimed to educate the local population on water quality runoff. Plants and shrubs were native and provide food and shelter for invertebrates, birds and marsupials. The project provides access for families to walk around the lake and enjoy the water views. Below are some photos of our work.

After 18 years the project has not lost its relevance, and more work like this is needed to treat our precious resource, WATER.

Some history on water pollution.

Invertebrates enjoying the habitat

Invertebrates enjoying the habitat

Sculptures in the water

Sculptures in the water

Why green your building?

A quick summary of the benefits of green infrastructure and a Wall St Video explaining them. The main points are that green infrastructure is great for cities because of the following reasons:

  • Improved water management both quantity and quality
  • Reduced energy costs and carbon emissions, up to 27% KWH usage.
  • Cools the city whist improving aesthetics
  • Recreational value to improve property amenity, beautiful roofs provide a secluded garden for city dwellers. 
  • Great for growing local food
  • Provides biodiversity in a city

I have example projects where the above benefits are tried and tested. Give me a call and I can show you. Robert 0468 787 071.

Benefits of green roof

Benefits of green roof

Australian native biodiversity for a Green Roof is possible

Over the past 3 years I have been studying Coastal Sandstone Plateau Rock Plate Heath for its resilience. I am particularly interested in the way plants grow on shallow soils around Sydney in this vegetation type. There is a wide variety of diversity in both flora an fauna in this heath. There are some special plant adaptions and symbiotic relationships that make these plants thrive in harsh conditions. Wherever plants grow there is a rich abundance of lichens, mosses and insects above the ground. The symbiotic relationships ensure moisture is retained and nutrients provided to sustain a growth. Below the ground fungal mycorrhizal associations are related to nutrient exchange with fungus benefiting from sugars created by plants photosynthesis. The plants benefit from the nutrients available from the huge surface area that fungal hyphae provide. When plants are under extreme stress, after a few months without rain some take a deep red colour in their foliage. This could be a defence mechanism which is often associated in red leaves and toxic compounds.  Apart from field research my experiments included growing these plants in green roof modules over a 3 year period.  I observed how species persist and thrive. On the ridge tops around Berowra plants will grow in 15mm of soil and are possibly decades old. I grew plants in trays 45mm deep with great results. Plants were grown from collected seed and cuttings, I included lichens and site soil to include fungus. It is my hope that emulating this vegetation type on our buildings that biodiversity, particularly birds will have their habitat enhanced in our urban environment.

There are many species, some include Leptospermum arachnoides, Calytrix tetragona, Gahnia aspera, Patersonia sericea and my favourite Micromyrtus blakelyi.

Green roof plant Baeckea brevifolia turning red in a dry summer period. 

Green roof plant Baeckea brevifolia turning red in a dry summer period. 

Green roof plants here is Baeckea and Casuarina nana growing in a mere 45mm depth of growing media for over 3 years in the same tray.

Green roof plants here is Baeckea and Casuarina nana growing in a mere 45mm depth of growing media for over 3 years in the same tray.