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Power Plants: Can Electricity Boost Crop Yields?

Power Plants: Can Electricity Boost Crop Yields?

This article featured in our new members-only magazine, HortInsightsJoin us today as a member and you will receive our magazine by email every two months.


Could electricity help to reduce insect attack, boost yields and enhance the quality of fruit and vegetable crops? A series of research programs in China is underway using electric fields inside glasshouses, according to a profile article recently published in New Scientist.

Scientists are reporting that yields can be boosted significantly when the crops are exposed to a mild electric current, with yields of lettuce and cucumber increasing by up to 40 per cent. Research in Mexico using maize also reports that a mild electric current provided through soil electrodes increased the yield of the crop by over 85 per cent, a huge increase for a crop that feeds billions of people.

It is all a little bit mysterious. Research into the benefits of ‘electroculture’ is not new – experiments as far back as the 1880’s seemed to show that electricity stimulated crops. Finnish scientist Karl Selim Lemström was studying the northern lights in Lapland and noticed how well fir trees grew there, despite the harsh cold conditions. In his experiments on various crops, there were mixed results, but carrot and pea crops that he grew in France showed dramatic increases of 75 per cent and 125 per cent respectively.

Renowned English scientist J.H. Priestley replicated the experiments and also found that cucumbers increased their growth by 17 per cent, adding weight to Lemström’s claims. Oliver Lodge strung electric wires over a wheat crop which performed 24 per cent better than those without electricity. At the end of the First World War, the UK established an Electro Culture Committee that trialled cereals and potatoes, and despite apparent increases in yield of around 20 percent, they deed the cost of electricity to be too high to make these yields economical.

The renewed push for research in China came about more from a push towards sustainable and eco-friendly agriculture than yield gains. Some of the research showed that electricity deterred insects and even bacteria, as a result of the production of charged particles that ‘zap’ these pathogens.

Scientists remain uncertain as to the exact mechanisms by which electricity might stimulate plant growth. Some believe that electricity simulates the electricity generated by lightning, suggesting that the electricity is a precursor to the arrival of nitrogen-rich rain. If, however, the electricity appears without rain perhaps that causes the results where sometimes yields did not increase.

“The mechanisms that underpin these observations remain elusive. But there is definitely a very interesting interaction between plants and their electrical environment – time will tell how this might actually benefit agriculture”, says Dr Ellard Hunting from the University of Bristol in the UK. “In a nutshell, plants do respond to electric fields”, says Jean Yong at the Swedish University of Agricultural Science at Uppsala University. “It is logical that an electric field could speed up the flow of crucial nutrient ions like nitrate or calcium. But the research is inconclusive.”

Perhaps with the rise of electricity-generating films for glasshouses and cheaper solar panels, more research into electric crops might be on the way. Maybe you’ll get your vegetables free of charge?

The original article was published in New Scientist on 24 August 2019 by Donna Lu and David Hambling.

Member Spotlight: Meet Christian Jenkins MAIH RH0157

Member Spotlight: Meet Christian Jenkins MAIH RH0157

This article featured in our new members-only magazine, HortInsightsJoin us today as a member and you will receive our magazine by email every two months.


Christian Jenkins MAIH RH0157 recently became our newest Regional Convenor for the Victoria region. Christian is a highly-regarded landscape design specialist based in gorgeous Grovedale, right near Geelong in Victoria. With its proximity to Port Phillip Bay and the Great Ocean Road, Christian services clients throughout Victoria.

With an impressive array of awards, Christian is well-known in the landscape sector. His designs have been recognised with two awards in 2019: the People’s Choice Award for the ‘Dreaming’ garden and the SILVER Gilt Award at the Melbourne International Flower and Garden Show, as well as Gold at the New Zealand Flower and Garden Show 2018 winning Design Excellence, and Horticultural Excellence Awards and Gold in 2017.


Christian Jenkins MAIH RH0157 landscape design specialist. Image: Christian Jenkins Landscape Design.


Hello Christian! Tell us how you started out and built up a successful career in horticulture and landscape?

From a young age, my home duties were mowing the three-quarter acre lawn with the push mower, long summers at the beach, and being surrounded by nature created my love of the outdoors. I applied for an apprenticeship as a curator at a private school and missed out – he explained that a job as a gardener would shortly be available. For the next two years l was based at the Ivanhoe Grammar School gardens, and I attended Burnley College studying Horticulture with a love of garden design.

I spent many years with a wonderful landscaper who helped me find my craft in construction, design and horticulture. In 2003 I created my first Show Garden at MIFGS – something happened at that time, being in this creative forum surrounded by a wonderful selection of 100 year old trees, next to the city, in autumn the energy is addictive!

This led me to creating nine garden shows in a row, returning to do another seven from 2015 with two in New Zealand. This forum allows one to create garden designs that are more playful than I would generally create for clients. The awards and exposure that MIFGS has given me has helped my career.


‘Japanese Garden’ This Gold Medal Winning Garden was constructed for the New Zealand International Flower and Garden show in 2017. Surrounded by a lush green tapestry of tropical plant life, this boutique resort style garden includes an island style hut with contemporary furnishings. Image: Christian Jenkins Landscape Design.


What inspires and influences your award-winning design solutions?

Last year’s design at MIFGS “Dreaming” featured a sculptural metal pergola in the shape of a leaf. I also designed and built a 1.7m high sculptural egg that was painted by an Aboriginal artist from Uluru.

Getting back to the question, I am at the stage in my designing career where nature inspires me, without a doubt the greatest designer of all! As we are all horticultural enthusiasts I am inspired daily. The wonderful forms of dried seed pods amaze me with their artistry and I often think I would love a life-sized pod in the garden or how I could make one. Finding a point of difference as a designer is always the challenge, and most of all I like to challenge myself with the design concept. I love architecture and my designs generally include an outdoor room or sitting structure of some sort.

My love of water is always included in my designs with the reflective qualities the water brings, the calming influences and the wonderful soothing sound constantly brings me back to working with this medium. Functionality is also a major priority for my gardens, and I ensure that people can always enter my gardens and go on a journey to a calming sitting place.

To win awards at garden shows you must be fortunate to have wonderful plant sponsors, so displaying a wonderful selection of plants and trees of the highest quality brings the design together, and generally securing my plant sponsor for a show will quite often determine the style of my garden. Last year at MIFGS I worked with Carl from Botanix Nursery, Joel from Tall Trees and Michelle from Established Tree Planters and with their enthusiasm and love for MIFGS that helped me make “Dreaming” a celebration of Australian native plants.


Award winning garden for the 2019 Melbourne International Flower and Garden Show. This Garden is called Dreaming and is a tribute to the native parts we are so lucky to have in Australia. This Garden won People’s Choice Award 2019 and the Gilt Award 2019. Image: Christian Jenkins Landscape Design.


What is your advice for fellow horticultural professionals in navigating a rapidly-changing world?

I really find this a difficult question to answer – the world is changing very quickly and both agriculture and horticulture will be relied upon and have even greater importance in the years to come. Making organisations stronger, more approachable and exchanging our knowledge with each other will be very valuable. To remain successful in our chosen field we must be constantly evolving as a business owner, improving our existing skill set, looking to strengthen areas for improvement.

The great thing about our industry is artificial intelligence won’t be able to prune the roses, our best practise comes from our home garden so keep experimenting at home, and putting ourselves outside our comfort zone always creates great results. The changing world needs to get back to basics, and the simple things in life bring the most enjoyment – our industry brings so much enjoyment to so many age groups.

What big trends do you think horticulturists should look towards in 2020 and beyond?

Rainwater harvesting is something we can all do, and my home in the Otway Ranges relies solely on rainwater. Both local councils and governments support rainwater capture for sustainability and resilience.

The connection between mental health and nature will only become more important every year, with wellness gardens to become more popular. Fruit trees need to be planted more often using dwarf varieties and our gardens need to be planted with thoughtfulness for our local wildlife. Overall the design style will be less and less formal – I would like to think naturalistic gardens will be more common than a structured garden, with plant selection becoming increasingly important with the harsh environmental conditions.

I think we need to experiment more with soil media in the garden with the standard garden blended soil sold by the landscape supply yards needing some clever input. The houses are bigger and the gardens are smaller so we must continue to be creative with the small spaces.


Check out Christian’s beautiful designs on his website and social media – visit and stay tuned for news and updates from our Victoria region.

Andrew Prowse Landscape Architect Awarded For the Stunning Cairns Performing Arts Precinct

Andrew Prowse Landscape Architect Awarded For the Stunning Cairns Performing Arts Precinct

This article featured in our new members-only magazine, HortInsights. Join us today as a member and you will receive our magazine by email every two months.

Images: Andrew Prowse MAIH RH0053

The Cairns Performing Arts Precinct by CA Architects, Cox Architecture and Andrew Prowse Landscape Architect with Cairns Regional Council has won Queensland’s top prize for urban design, the Minister’s Award for Urban Design.

The Precinct was once a place viewed as dangerous and unattractive, sited next to a major highway at the edge of the Central Business District of Cairns. Residents and visitors alike tended to avoid it and the few plantings mainly consisted of mature figs and little else. Now transformed into an incredible, vibrant precinct, it is rich in indigenous planting specimens, with showy foliage and flowers, lush tropical greens and carefully-planned architectural features. The result is absolutely stunning, an amazing transformation making the precinct a top Cairns destination.


Mucuna novo-guineensis – the New Guinea Creeper

“Our goal was primarily to maximise the difference between Cairns Performing Arts Precinct and the popular Cairns Botanic Gardens”, explains Andrew Prowse MAIH RH0053.

“We set out to create a unique and distinctive area that made the best use of tropical plant selections. With their fast growth rate and size, we built a structural pergola to direct their growth into pleasing arches that bring shade and overhead form. This pergola creates a vast outdoor gallery room with cameos of significant people associated with the park over the years and a selection of flamboyant foliage plantings giving the park a distinct local and tropical experience”, said Andrew.


Shower of Orchids Vine – Congea velutina


Jade Vine – Strongylodon macrobotrys, the milky green vine from the Philippines. These vines are only found in the tropics and rapidly form gigantic vines that grow up forest trees and along the rainforest canopy. Often seen at the edges of clearings.


The jury said the precinct offers a valuable, high-quality contribution to the urban fabric of the city, ticking all the boxes – it challenged the status quo, demonstrated leadership and design excellence, and will leave a lasting, sustainable legacy for the broader community.

The jury said “the seamless integration between theatre infrastructure within the parkland allows visitors to experience the open space all year round, even when performances are not scheduled, contributing to the civic life of the city. The beautifully-executed gabion rock walls of the parkland stage deliver a clear sense of performance and authority to the overall placemaking qualities of the space.”

The Registered Horticulturist membership is increasingly sought after as a marker of professional quality, and Andrew is proud to have led a project with such stellar outcomes.

Hort Journal: How This Urban Farm is Bringing a School Community Together

Hort Journal: How This Urban Farm is Bringing a School Community Together

By: Michael Casey MAIH RH0106

This article first appeared in the February 2020 issue of Hort Journal – visit for the full edition.


Today we are confronted with many new environmental and social problems that we have in some cases never seen nor experienced. From water shortages and in Melbourne lower than normal rainfall, increased summer fires, an urban sprawl that is moving at an unprecedented rate and food security issues that accompany this desire for land, we are not short of witnessing the effects of the Anthropocene era that we have now entered.

What I do see with my work with schools and currently with one school in particular, is that the students are ‘hungry’ to learn more about how they can assist with change and how their passion can work towards greater awareness and help for our changing world.

Introducing Food Gardens

Three years ago the introduction of food gardens to the school grounds at Catholic Regional College in Sydenham, and their use in the students’ education was just seen as another teaching aid. Now, however, the passion and desire to grow more food, understand food security, the concept of paddock to plate has allowed myself alongside the school and more importantly the students to create a 4000 square meter food garden comprising of a citrus orchard, raised planters, wicking garden beds, open garden beds and container gardens all providing seasonal fruit and vegetables to the school community and the onsite café and restaurant.

The Garden That Brings People Together

This garden is now seen by the school community as not only a teaching garden but a place to visit, understand, taste, socialize, rest and communicate in. This garden has brought the school community together. It has given voice to the students who regularly share the information via social media or through the school communication avenues, teachers are embracing the garden and using it for their own classes (hospitality, business studies, etc.) and more importantly, it gets the parents involved who both visit the garden and receive regular bundles of excess crops brought home by the sons and daughters.

I’m currently working with Year 11 and 12 VET students (Vocational Education & Training) running both the Certificate 2 Horticulture as well as combining it with my ‘Naturing Education’ which is a mentoring and skills-based program promoting both industry and life skills. Together we have been managing the urban food garden inside the school grounds. The need for the introduction of a sustainable urban farming model and more importantly the teaching and promoting of social responsibility was close to my beliefs that, to educate these students about the future issues we face was to first have them understand the fundamental basics of current food production, consumption and waste.

Understanding the Concept of Paddock to Plate 

The students needed to analyse what they have been taught by society regarding food production and harness both the ways food and waste were dealt with and how current methods need to change to a new more sustainable model. To start with I had the students understand how long it takes to grow food and the concept behind seasonal produce. They needed to understand how long it takes plants to grow from seed to plate as this was new to them.

What society has taught them is to take for granted that food will always be on the shelves at supermarkets and I needed this to be totally removed from their everyday thinking. The students also needed to experience consumption of foods from the consumer angle and in this case the school café and restaurant that required vast amounts of food for their menus and feeding hungry customers.

The students were able to see first-hand how much work went into the growing of a certain crop and how far that actually went in regard to feeding a room full of people. The growing of food also included the hospitality students who would work alongside the horticulture group. Here the two trades can meet and discuss their needs and wishes with seasonality of foods, taste, quantities and varieties all discussed between these two professions. This is where the school garden has allowed the two classes to benefit from both the knowledge of the ‘grower’ to the experience and knowledge of the ‘preparer’.


Horticulture and hospitality students working together in the food garden (Image: Michael Casey)


This was made clearer when we asked the students to bring their families to a dinner at the restaurant. The students were asked to invite their families along to both showcase their work in the garden throughout the year and to see first-hand how the paddock to plate concept works and to how much time, labour and resources goes into producing a crop for consumption. The shock displayed by most students was that the restaurant had taken most of a certain crop from their garden that had taken 14 weeks to produce leaving them with little extra for future use, and this was for one night at the restaurant.

Not only did the dinner highlight the use and consumption of food but it allowed for the parents and the students to sit at dinner and hear stories and discussions from their parents about their own experiences growing food both currently and when they grew up. The stories of their parents going out to the backyard to pick food for dinner was a concept unfamiliar to most of these students.

What I think was the most amazing part of this sharing of information was the different cultures sharing how the growing of food is so important to them and their communities. It also allowed the students to understand some different crops that are the backbone to some people’s diets.

The garden recently received the Best Edible Garden Award in the 2019 Victorian Schools Garden Awards. This award goes to not only the students who worked tirelessly on the garden throughout the year but also to the school community that understood the need for a garden like this to exist. My visions for this garden and the students that work in it is to be a champion of urban farming in school communities and to have the education of food security and climatic issues be taught at an age that gives these students hopefully new career paths to pursue.


Michael Casey pictured with VET students at the recent Victorian Schools Garden Awards (Image: Michael Casey)


I acknowledge that today’s children are the creators and leaders of tomorrow and food security, sustainability, social responsibility and entrepreneurship sit within their reach. I’m here to help them harness and embrace this.

Michael Casey is National President of Australian Institute of Horticulture and Director of Evergreen Infrastructure and MJC Horticulture and currently sits on the council with Therapeutic Horticulture Australia. He can be contacted at or

Hort Journal: Registered Horticulturists in Demand

Hort Journal: Registered Horticulturists in Demand

By: Wayne Van Balen MAIH RH0027, Manager, Registered Horticulturist Programme

This article first appeared in the December 2019 issue of Hort Journal – visit for the full edition.


More and more government and large industry contracts are requesting Registered Horticulturists to achieve the best results for their projects.

The Australian Institute of Horticulture (AIH) Registered Horticulturist (RH) program has been in existence now for approximately eight years. AIH Convenors have worked hard in a very positive manner to build regional networks in a truly national organisation. The organisation benefits significantly from the activities and successes of collective regions.

AIH, as the Peak Body for the profession of horticulturists, is obliged to provide new and valued programs to advance the interests of Registered Horticulturists in Australia. This includes those working in the production, amenity, environment and government sectors. The profession we are dealing with is becoming much more sophisticated. Successful nursery wholesalers need to know they are dealing with educated professionals who understand stock quality, species habits and alternatives.

It is not simply a matter of having a plant list. Well educated horticulturists need to understand biological interrelationships between alternative species in specific environments. Retailers likewise will benefit from customers receiving cutting edge support. Government and large industry contracts will be demanding professionals with sound, up-to-date and broad-based knowledge.

Many Landscape Architects, as well as Government and Industry contracts, require the involvement of Registered Horticulturists in achieving the best results for their projects. There are currently over 100 Registered Horticulturists in the program, with growing interest in this membership category. The program requires RHs to maintain a minimum of 24 relevant professional development points over any 24-month period.


Tree Pruning Workshop with Ian Gaston (Image: Jane Van Balen)


Regional Hubs

The AIH has an excellent system of Regional Convenors based in definable regional localities. Whilst general information is important, a focus on regional issues, e.g. NSW Southern Highlands or Queensland South East region, can be useful in addressing specific regional issues. This also allows another level of networking and mentoring and also mitigates potential problems and losses. For example, it provides opportunities for regional members to gather on an informal and semi-formal basis.


Citrus Workshop with Rob Engalls (Image: Wayne Van Balen)


Program Integrity

To ensure the integrity of the program, random audits are carried out in relation to RH logbooks which are kept up-to-date by members. To participate in the program, members need to have an appropriate level of qualifications and experience and carry professional indemnity insurance. The great benefits of the program include:

  • Participants keep up-to-date with changes and advancements in the profession and associated industries.
  • A current and strong network of associated professionals.
  • Potential for cutting edge collaboration, particularly on significant projects.
  • Critical awareness of up-to-date standards and methods which avoids duplication, mistakes and inefficiencies.
  • In an ever-increasing number of projects, developers require Registered Horticulturists to certify the quality of plant stock and methods of planting in accordance with the current standards.
  • Major projects, whether they be large scale residential, recreational or public open space, are requiring professionals who have a broad range of horticultural knowledge and skills. The principal contractor can be confident that they are using a professional who is a member of a well-administered program and who is responsible to their peers.

Award Winners

Current examples of high value, award-winning projects that have demanded or benefited from the use of Registered Horticulturists include:

  • Barangaroo in Sydney
  • Gateway project in Perth
  • War Cemeteries projects in Brisbane and Papua New Guinea
  • Dawn Andrews Park constructed by QM Properties Pty Ltd in Queensland.

Focus on Horticultural Science and Management

Our calendar of Continuing Professional Development activities and events gives members information on a broad range of activities they can participate in.

The following topics form the core of workshop training:

  • Diversity of available plant materials and plant biology.
  • Plant nutrition.
  • Pest and disease management.
  • Soil science.
  • Efficient water management.
  • Interrelationships with associated ecologies and the environment.
  • Needs and benefits of greenspace development.
  • Food security.


Soils Workshop at Ryde with Simon Leake. (Image: Wayne Van Balen)


The RH movement is more than an advertising showcase of horticulturists. It is about seeking accountability and commitment from those in our communities who:

  • provide the essential amenity of greenspace.
  • play an integral role in managing the influences and impacts on climate change.
  • manage natural resources and are accountable for the impacts on our environment.
  • maintain the availability and quality of water.
  • have a direct role to oversee the supply of quality food.
Top Choices For Indoor Plants With Benefits

Top Choices For Indoor Plants With Benefits

The world seems to have brought everyone home lately, destined to stay at home for the foreseeable future. This has us thinking about the real and proven benefits of indoor plants for fostering life and lushness in our homes.

A study by researchers at RMIT in Melbourne formed the basis for the horticulture industry’s Plant Life Balance campaign, with a range of styles that included “Paradise Traders” and “Dark Matters” with a strong focus on indoor foliage. By using plants with large leaf areas, distinctive foliage colours and unique architectural forms, you can create a whole new furnishing for your home.

With the help of our expert plantsman, Michael Casey MAIH RH (yes, he’s our President too but here he’s on official plantsman duty), we’ve pulled together some top plants with benefits:

The Heavy Breathers

“We all know that plants produce oxygen. Well, these beauties are the heavy breathers of the indoor plant world, enriching your indoor air and providing amazing foliage impact”, Michael said.

  • Epipremnum aureum – this popular vine is often deeply-variegated and hugely popular in trendy inner-city cafes with a millennial vibe. It’s really tough and very beautiful with buttery yellow streaks and glossy deep green trailing vines.
  • Phoenix roebelenii – the ‘Pygmy Date Palm’ is a small-growing palm ideal in pots with arching foliage over a stocky trunk. Its green foliage is an ideal background plant for more showy indoor species and it likes a bit of outdoor time now and then.
  • Philodendron sp. – an old classic but the new varieties are not as overpowering as the older types. A great choice for indoors or shady outdoors and very resilient with notched foliage.
  • Nephrolepsis exaltata – the ‘fishbone fern’ is perfect for a sunny window and you’ll often see them used on green wall plantings as a feature that cascades outwards.



The Foliar Filters

Michael describes this group as plants that absorb the chemical gases that come from furniture, plastics, flooring and other man-made products in the home. These materials release tiny amounts of VOCs (Volatile Organic Compounds) which can cause irritation.

  • Asparagus densiflorus – the asparagus fern is best kept indoors as it can escape outside and become weedy. But indoors it’s a tough, durable plant with drooping fronds, and it’s impossible to kill.
  • Tradescantia sp. – The ‘Trads’ are an excellent planting feature indoors, and come in greens and purples for foliar impact. Also very tough with sappy stems that you can easily grow from cuttings.
  • Hoya sp. – the mystique of Hoya is well-known, with its climbing vines, waxy green leaves and really unusual starry white-purple blooms. It’s an excellent indoor feature and very hardy.



Shy And Retiring Types That Avoid The Limelight

“If your place gets dark and gloomy, indoor plantings will certainly add a splash of drama and focus. Plants that tolerate lower light levels sometimes originate from forest ecosystems, or have a lower growth pattern that enables them to cope with lower light availability”, explains Michael.

  • Sansevieria trifasciata – the classic upright stems of ‘Mother In Law’s Tongue’ are an indoor favorite, not least because they are attractive with white streaks and sometimes yellow and cream colourations. They also work well outdoors and appreciate a little time in brighter conditions now and then.
  • Aspidistra elatior – the classic ‘Cast Iron Plant’ is the toughest plant we know, and tolerates anything. However, it does best with a regular clean and good soil that promotes its glossy upright foliar habit. Literally, tough as old boots.
  • Spathiphyllum sp. – the iconic ‘Peace Lily’ is a perfect indoor plant and appreciates rich soil and regular watering. It will grow to fill its container so you can be generous with the pot size and it will become a focal point in your room when their white flowers emerge.



The Show Offs

“These plants are ideal where they can show off their form and style on their own merits”, says Michael.

“They are great for a bright and welcoming entrance or feature in a room”.

  • Ficus elastica – the ‘Rubber Plant’ is popular, most often as stand-alone feature plants that sit on their own in a bright corner. They like rich soil and a good-sized pot, and appreciate you cleaning their leaves with a damp cloth every now and then. Often they have purple colouration on the new leaves.
  • Ficus benjamina – the classic indoor fig forms an attractive glossy-leaved shrub that will get very large if you let it. The whitish-cream of the stems and the bushy, glossy leaves make it an excellent indoor feature, best kept at a modest size.
  • Crassula ovata – the ‘Jade Plant’ or ‘Money Tree’ is a hardy succulent with brittle stems and glossy leaves. It will tolerate dry but as a succulent (not a cactus), it prefers slightly damp soil without over-watering.

Enjoy them all with good quality potting soil and regular but not overdone watering. Good luck!



AIH Walk & Talk: Taking a Closer Look at Roses In Modern Landscapes

AIH Walk & Talk: Taking a Closer Look at Roses In Modern Landscapes

In our February Walk & Talk, the Institute took a group of rose enthusiasts to Green E Roses in Galston NSW. For professional horticulturists and landscape experts, there is still plenty to recommend about roses in Australian gardens and landscapes.

AIH designed the tour to showcase the diversity of modern roses and seek expert guidance from fourth-generation rose growers, Klaus, Brigitte and Stephen Eckhardt.

Modern Applications of Design Using Roses

The Walk & Talk centered on continuing to use roses in rapidly-changing landscape designs with space limitations and changing consumer preferences. It is, however, the diversity of modern and species roses that gives them such incredible versatility in landscapes, enabling huge rambling climbers through to compact, almost bedding specimens to suit the landscape and preference.

Some varieties grow to become very large and are best left largely to their own devices – like the huge Marie Van Houtte that occupies the morning-sunny corner as you enter the nursery. One plant covers around six square metres and looks largely after itself.

Others such as weeping standards can create flowers at height, enabling the designer to plant beneath them. Brigitte pointed out that standards grow from the ‘top part’ – an important consideration since the plant will put on upward growth once planted.

Take-Home Messages

  • Designers should absolutely consider roses in modern landscapes because the varieties on offer can deliver a result for every customer in the form of shape, colour, scent and habit.
  • Focus on soil health and judicious pruning. Feeding the plant will ensure that the leaves feed the flowers. As Klaus says “roses get big before they get beautiful” – those big blousy blooms need a lot of energy and food to get going, so creating good soils will deliver results without too much foliage growth.
  • Prune according to the type: the harder you prune, the more the plant has to create new shoots to support flowers, so you can moderate the growth of flowers by pruning harder or more moderately. For climbing roses, just trim them back gently, since hard pruning will create long sucker shoots that take longer to bloom. You can also train roses along wires or espaliers, and they can tend to flower more evenly along a horizontally-trained branch.
  • Black Spot fungus (Diplocarpon rosae) is a problematic fungal organism that infects older leaves during conditions of high humidity. Stephen advised that watering in the morning is better than at the end of the day to avoid the longer exposure to water that encourages fungal spore germination (the spores need around seven hours of water to infect a leaf). Black Spot is unavoidable but can be minimized with good hygiene and plant health.

The rather enormous ‘Marie Van Houtte’ occupies pride of place in morning sun.

‘Marie Van Houtte’ herself.

Brigitte tours the group through the extensive nursery.

An unusual single rose variety.

Stunning colour and pattern features make roses ideal cut flower specimens.

Gorgeous varieties in all shapes, forms and sizes.

Stephen demonstrates T-grafting and chip-budding.

“A rose will often push out shoots from the food stored in the internodes before it develops roots. So what we do as rose growers is graft onto good, established rootstock using chip-budding mostly. It ensures the graft is placed onto strong roots and the long-term benefit over the lie of that plant is definite, compared to just growing on its own roots. The flowers are larger and the plant stronger”, Stephen said.

Klaus demonstrates pruning principles.

“Pruning a rose offers the greatest benefit to its vigour and productivity”, Klaus explains.

“You can prune as hard as you like as long as it’s above the graft union. Pruning just above an outward-facing eye will push the following growth outwards and keep the centre clean. However you can also prune inwards if you wish for a more compact upright rose in an enclosed space. But, overall, pruning will give you better results than fertilizer in healthy plants.”


With thanks to Klaus, Brigitte and Stephen Eckhardt for their wonderful hospitality and generously sharing their knowledge. Visit or find them on Instagram and Facebook.

Thanks also to Chris Poulton FAIH RH for convening the event with David Ting MAIH RH and Wayne Van Balen MAIH RH.

We appreciate the support and attendance from members of the Rose Society of NSW.


Bushfires: Aftermath Suggestions for Clients

Bushfires: Aftermath Suggestions for Clients

By Wayne Van Balen MAIH RH0027, 8 February 2020.


Topic 1: Assessing fire damaged plants to establish whether they are alive or should be scrapped

Burning is not considered authorised clearing. A useful reference is the NSW Government Local Land Services publication, “Managing Native Vegetation after a Bushfire Emergency“. There is some allowance for the removal of burnt vegetation if there is an imminent risk of serious personal injury or damage to property. It is reiterated that reference should be made to the legislation. A further reference, particularly for commercial horticulture crops, is Hort Innovation’s “List of Information for Those Affected by Bushfires“.


Many affected plants will look dead or badly damaged but have a strong ability to regenerate.

Adaptions include, for example:

  • bark thickness.
  • in relation to Eucalyptus, resprouting from epicormic shoots in the trunk or from underground organs.
  • Regrowth from underground lignotubers e.g. Banksia.
  • Leaf-sheaths e.g. Xanthorrhoea, Lomandra, Cycads and tree ferns.
  • Fire-stimulated seed release.
  • Improved seedling germination, stimulated by seed rupturing, smoke and ash.
  • Flowering stimulated in geophytes.

Rainforests are a different issue and normally retard the fire, however rainforest boundaries can be moved back by fire, particularly when there are highly flammable grasslands on their flanks.

Ornamental Species

  • Ensure that any dangerous material where there is imminent risk of serious personal injury or damage to the property is removed. It should be noted that many species have an ability to regenerate and some time should be given before final assessment is made.
  • During the restoration phase, less fire-hazardous species can be researched and utilised.

Topic 2: What Next – How Can We Assist in Garden Regrowth

  • Control erosion.
  • Control weeds.
  • Use well-rotted mulches, if available.
  • Water regenerating plants where possible.

Drier and hotter conditions are causing skepticism about the ability of the ecosystem to bounce back. This is where consideration of different species that handle hotter and drier conditions might be made. Macquarie University has been carrying out research in this area.

Topic 3: Soil Remediation

Issues include:

  • Microbiology:
    • There is short term destruction of microbiology.
    • Micro-organisms in the upper layer of soil also have a strong ability to regenerate. Some assistance can be given to the restoration of microbial communities by adding organic matter which will improve the soil’s water holding capacity. This will also feed and attract earthworms and essential soil microbes.
  • Ash:
    • Ash comprises very fine particles and can cause the soil to become hydrophobic. In some areas, it can lead to the soil becoming too highly alkaline, but on acid soils, some ash can be beneficial.
    • Heavy rain can cause too much ash to be deposited in the water catchment and cause water pollution.
  • Pollution:
    • Fire-fighting retardant residues can lead to a pollution problem. It is recommended that details be provided on which retardants were used and how the residue can be managed.
    • Some building materials, including paints and asbestos, can pose a health hazard and require specific management.

Topic 4: Planting Decisions

Firstly it should be emphasized that all plants will burn and fire intensity and circumstances will vary.

Planting decisions to minimise fire risk and damage should consider the following points:

  1. Trees that reduce and retard ember attack are favourable. ie those that act as a heat barrier and shield from embers.
  2. Trees that slow the passage of flames should be used.
  3. Moisture in the leaf tissues may be enough to stop the fire or reduce wind speed as the fire approaches.
  4. Trees and shrubs should be lush with high moisture content and be low in flammable oil content.

Some examples of useful deciduous trees include:

  • Liquidambar
  • Oak trees
  • Elms
  • Most of these will recover well after a fire.
  • Other deciduous small trees that could be used include Pyrus, Prunus, Malus and Mulberries.
  • The dense foliage provided by evergreen exotic plants like the evergreen Magnolia species would also be satisfactory.

Some other examples are native tree species such as:

  • Tristaniopsis laurina (Water Gum)
  • Lilly Pillies
  • Hymenosporum flavum (Native Frangipani)
  • Cupaniopsis anacardoides (Tuckaroo)
  • Brachychiton acerifolius (Illawarra Flame tree)
  • Glochidion ferdinandi (Cheese tree)
  • Elaeocarpus species
  • Ficus

Examples of shrubs to use:

  • Hydrangea
  • Viburnum
  • Escallonia
  • Photinia
  • Coprosma
  • Plectranthus
  • Oleander
  • Aloe
  • Acacia iteaphylla
  • Correa

In drier areas, the list of native low fire risk species should be considered as the use of many of the exotic species would have higher water requirements.

Examples of useful Groundcovers:

Succulents, Hibbertia scandens, Dichondra repens, Dianella, Lomandra, Ajuga, Dampiera,  Scaevola, Pigface, Myoporum and Catmint.

Some of these can slow down a fire and reduce spot fires and reduce fire energy before igniting a house.

Some early fire prevention and minimisation measures include:

  • Get rid of rubbish.
  • Clear weeds and debris.
  • Cut back overhanging branches and dead growth.
  • Remove dead grass and fallen leaves and bark.
  • Remove flammable wood-based mulches (replace with Gravel or pebble).
  • Use of lush groundcover plants such as lawns closer to the dwellings.
President’s Report February 2020

President’s Report February 2020

Dear Members,

I hope your start to the year has been smooth and not affected by either extreme heat, fires or flooding rains?

It does make you think more about the current condition our climate is in and what impact it not only has on us but our industry. Last year’s conference highlighted the hard work being accomplished by members of our industry but it also highlighted the amount of work we still need to do and how we need to continue to push our industry and learn more about how horticulture can assist in a changing climate.

This year the institute celebrates its 60th year as the peak industry body representing horticulturists in Australia and Southeast Asia. We will be hosting our awards night in Sydney this October along with our national conference that was very well received last year in Perth. The conference will follow on with a similar theme to last year highlighting the works of horticulturists in our changing climate. Please keep an eye out for the communications regarding these events.

We have also worked alongside our industry colleagues at Interior Plantscape Association to organise a three-day tour of Singapore gardens to coincide with this year’s Singapore Garden Festival. This event has been such a success we have nearly sold out of the limited seats we had available. This will be a great event and we thank both IPA and NParks for their assistance in organising this event.

The National Council and myself will be attending MIFGS this year in Melbourne and invite anyone wishing to catch up to contact myself or AIH directly to organise a catch up.

I look forward to a big year ahead and welcome all our new members that have joined our organisation at the start of this year.

Michael Casey

AIH Meeting & Talk: Designing & Maintaining Public Gardens

AIH Meeting & Talk: Designing & Maintaining Public Gardens

By Patrick Regnault FAIH RH


The last meeting of the year saw us at the Gold Coast Botanic Garden. Our host was Alex Jakimoff, President of the Friends of The Gold Coast Botanic Gardens.


Alex Jakimoff president of the Friends of The Gold Coast Botanic Gardens.


Whilst walking through the gardens Alex spoke about their creation, the work done by the five council staff and volunteers, who give a total of twenty hours/week to look after part of the Gardens. Those passionate and too often overlooked volunteers are an essential part of why public places and gardens are looked after as well as they are. We also need to remember that those same volunteers have accumulated a wealth of knowledge which we, as a profession, need to embrace and welcome into our midst.



Alex and the Friends have an ambitious project they are currently working towards which is a new Regional Biodiversity Centre. It would be situated in the Gardens and would be a plus regionally for the Gold Coast city, the hinterland and beyond.

This is what Alex had to say about it:

“The Friends are passionate about preserving and restoring the remaining natural environment of the Gold Coast Region, one of Australia’s biodiversity “hot-spots” which is one of only 36 on this planet. They have been working to develop a Concept Design for a Regional Biodiversity Centre located in the Botanic Gardens.

This “state of the art” Interpretive Centre will showcase and celebrate the incredible biodiversity of the region, over 1600 plant species with 88 of them being threatened species. An exciting innovative centre would feature a structural timber design with high environmental sustainability and function as an information, education and research hub for visitors and students”.

Some of the many roles of such a Centre would be to educate local and overseas visitors to create an educational forum for school children to learn about plant science, and to foster an understanding of the local flora and its interaction with the fauna.



Botanic gardens need to be supported, Botanic Gardens volunteer associations and professional organisations like AIH play a role in encouraging the different levels of government to concretely support those important botanical institutions.