Category: HortInsights

Say It With Flowers – But Probably Not This One..

Say It With Flowers – But Probably Not This One..

A few months ago we had a little bit of cheeky fun on the socials for Mother’s Day, which is usually the time of year you would celebrate your love and gratitude for mum with a bunch of freshly-picked fragrant blooms.

https://www.facebook.com/AustralianInstituteHorticulture/posts/3198603383501164

This is a fascinating plant that never fails to draw a crowd when its spectacular blooms emerge from the distinctive leafless spathe. The most memorable thing about Titan arum (Amorphophallus titanum) is its incredible odour, a feature that evolved to attract pollinating flies in the jungles of its home country, Sumatra and Indonesia.

This clever evolutionary partnership relies on the production of odorous chemical compounds at peak bloom, at which point the temperature of the inflorescence increases to around 37C and helps these chemicals becomes volatiles that draw in insect pollinators.

The energy required for such an incredible bloom means these plants only flower about every decade and between flowerings, the plants produce a single leaf of great size.

 

 

If you do like this flowering family, we recommend their more-modest relatives which include the well-known Peace Lily (Spathiphyllum cochlearispathum)

 

or the Cuckoo-Pint (Arum maculatum), which are much more suitable for mum when you say it with flowers.

What is Virtual Reality and How Can We Use It In Landscape Design?

What is Virtual Reality and How Can We Use It In Landscape Design?

By Matt Greenwood LEG Designer of Virtual Worlds

The way in which we as designers realise, represent and convey our concept designs is, like any form of technology, ever evolving.

We have seen this in the shift from delicate hand-drawn plans to impossibly precise CAD (Computer Aided Design) drawings and more recently to BIM (Building Information Modelling) where an intelligent 3D model is created through the documentation process.

We have also seen this in the way we present our work to the client, evocative illustrations and watercolours where ‘the hand’ is visible are almost extinct, replaced by computer generated 3D renderings and animations that aim to create a photo-realistic view of a future vision.

However the latest shakeup to hit the design and entertainment world has been the rapid development of Virtual and mixed realities. This technology can range from a simple 360º photograph, or playing Pokemon GO on your mobile phone, to hyper realistic video games on home entertainment systems. The unmistakable headsets worn by users flailing at seemingly invisible objects is now commonplace across many industries. Most importantly for designers and our clients, it offers a unique opportunity to design and showcase our work at what we would call 1:1- in other words, real-life scale.

But before we dive too far into the possibilities, what is Virtual Reality or VR? VR in the current everyday sense is the use of a headset that positions two screens, one in-front of each eye with lenses that provide peripheral immersive vision. What is displayed on these screens and how this is constructed is completely up to the individual designing the experience. Headsets are now commonly accompanied by headphones and handheld devices called ‘Motion Controllers’ that essentially track the users hands in 3-Dimensional space allowing interaction with digital objects.

Until recently the computing power and software to realise an interior space let alone a whole landscape has been out of reach. However we can now use this technology to not only design better exterior environments but also showcase this in an immersive and digital environment.

Virtual Reality As A Design Tool

As a designer the ability to put on a headset and be inside your creation offers unparalleled opportunity to create better landscapes, gardens, or outdoor environments particularly where there are changes of levels and more hard landscape elements. We can now send a 3D model that we are developing on the computer to a Virtual Reality headset and upon entering this digital world you get a sense of scale and awareness immediately that isn’t possible from a flat computer screen or a 2D plan.

This technology isn’t just representational, we are not only able to view designs, we can start to make notes and changes within this digital setting. This technology is now so precise that we can take real-world measurements from within virtual reality, which is excellent for getting that bench seat, or climber clad pergola to just the right height.

That is what we can do with one headset. Imagine what is possible when we start to add two or more headsets- we then gain the ability to have design meetings and presentations within the digital space itself allowing real-time feedback and discussions between colleagues in completely different offices, states even countries.

 


Side by side of the final built outcome and the design model in Virtual Reality at concept stage. By exploring a project in Virtual Reality during the design process we can start to understand the look and feel of spaces and moments.

Virtual Reality For You

It is all well and good for us to talk about the impact that Virtual Reality has on us and our design process, however what does this mean for the client?

Imagine, if you would, coming in for your concept presentation- we take you through the plans, the theoretical backing of the concept design and show you conceptual renders of your future garden. We then ask you to place the headset sitting on the table on your head and you are instantly transported to a full size representation of your future garden.

These are not just static environments or still images- there is movement, breeze, light and life. You are able to walk around this digital recreation of your future garden, getting a sense of the size of spaces, layout, and how the overall design may look and feel like upon completion.

You can experience the way that light casts shadow (accurate to your home’s geographical location) and as the sun slowly sets you get a glimpse of how it transforms at night with accent and path lighting all conceptually represented in a digital environment.

 


With dynamic lighting and time of day effects, Virtual Reality allows us to experience the space in all conditions, times and weather.

Virtual reality is not as daunting or difficult to navigate as it may seem- sure you can use the handheld motion controllers to teleport into the distance or pick up a wine glass- however you are more than able to just walk around the space like you would do in real life. The headsets are tracked in the real-world by a suite of sensors that enable you to walk, turn and crouch like you would normally – and your designer is always on hand to guide you as needed or draw your attention to a particular element of discussion.

Whilst in virtual reality there are a couple of things to keep in mind. Like any drawing, sketch or 3D render, what is being presented is conceptual only and elements such as materiality and planting is shown to invoke a sense of what the space may be like, with these details being finalised later in the technical documentation stages. The important elements to focus on in Virtual Reality, to get the most out of the experience as a client is; the positioning of objects, the scale of designed features (Wall heights, pergolas, terraces, path widths etc), and the ratio of hard landscape to planted areas.

So when having your next garden or landscape designed, perhaps consider the opportunity and experience that comes with having your design realised in a Virtual interactive setting. It certainly gives us the designers greater opportunity to resolve the design in the most tailored fashion whilst offering you- our client- a lasting digital experience and opportunity to visit your future garden well before its real-world construction.

 


Matt Greenwood is a Graduate of Architecture from the University of Melbourne, specialising in digital design. Prior to joining LEG on a full time basis, Matt taught virtual reality at the Melbourne School of Design and was instrumental in the establishment of the Virtual Reality syllabus.

Lisa Ellis Gardens is a multi-award winning design studio based in Melbourne. Since its establishment in 2004, the studio has formed strong ties within the industry – and is now a leader in its field. With a diverse portfolio of design work, the studio lives and breathes its strong values in every project. Principal, Lisa Ellis MAIH, published this article on her website in April 2020. Reproduced with permission.

What is a Succulent and What Makes Them Different From Other Plants?

What is a Succulent and What Makes Them Different From Other Plants?

By Jackie Warburton MAIH RH0164 (Photos: Jackie Warburton)

Succulent plants store water in their leaves, roots and stems and have much thicker leaves than other plants. The word succulent comes from the Latin word ‘sucus’, meaning juice, or sap. They are drought-resistant plants and have adapted to living in dry environments especially well.

Crassulacean Acid Metabolism (CAM)

Succulent plants store water in their leaves and stems and therefore can withstand long periods without water. This is described as Crassulacean Acid Metabolism (CAM).

Crassulacean Acid Metabolism is a carbon fixing pathway that has evolved in some plants as an adaptation to arid conditions. The Stomata (air holes) in the leaves are closed during the day to reduce evapotranspiration and open at night to collect carbon dioxide (CO2). Succulents have reduced stomata and photosynthesise from its stems rather than its leaves.

 

Figure 1

Figure 1:

CAM plants fix CO2 at night and convert it to carbohydrates during the day. This allows them to close their gas-exchanging pores during the day and minimising water loss.

This is a variant of the C4 pathway of photosynthesis and was first discovered in the Crassulaceae family of Succulents and there for named after the family. It has evolved in other plants such as Bromeliads, Orchids, terrestrial and ground dwelling plants such as Tillandsias, Euphorbia’s, Grapes, Lilium’s and some 25 other plant families.

Cacti are only CAM plants but one exception the Pereskia family. CAM plants can sit ‘idle’ and the internal recycling of the fixed carbon dioxide gets the plants through a dry spell.

 

 

Photosynthesis

There only three different ways plants can undergo Photosynthesis, taking carbon dioxide from the air, water, and roots as well as sunlight to transform into sugar and oxygen.

The first chemical made by the plant is a three or four chain molecule and is known as C3 and C4 and CAM.

 


Figure 2: C4 plants separate carbon fixation and the Calvin cycle by carrying out the pathways in different places. CAM plants separate them by carrying out the pathways at different times of day. These adaptations allow C4 and CAM plants to survive in environments where C3 plants cannot.

 

C3 Plants

C3 Plants are normal plants that don’t photosynthesise to reduce photorespiration and is the first step of the Calvin Cycle. About 85% of plants are C3 plants and like a cool wet environment to grow. Common C3 plants are all cereal grains such as wheat rice, barley, oats and include most trees and most lawn grasses such as rye and fescue.

C4 plants

C4 plants are created through the Calvin Cycle and made into an enzyme called RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase). They have a two-step fixation mechanism. C4 pathway is used in about 3% of all vascular plants such as corn and sugar cane where common habitats are hot and dry conditions. C4 plants use Mesophyll cells then evolve the bundle sheath cells and have the highest Carbon Dioxide (CO2) output and the lowest oxygen (O2) and water loss through the leaves.

CAM Plants

CAM plants have a wonderful adaptability to fix the atmospheric CO2 and minimise photorespiration. The slow growing desert succulents exhibiting CAM cycles have the slowest photosynthetic rate, while the species possessing C4 pathway possess the highest rates.

Stomata Open                    Best Adapted Environment

C3 Day                                 Cool, Wet conditions

C4 Day                                 Hot, sunny environments, high water, high light

CAM                                     Very hot dry climate, Low water availability.

 

The Calvin Cycle

Calvin Cycle is a chemical reaction performed by plants to ‘fix’ carbon from CO2 into three carbon sugars which then can be used to build other sugars such as glucose, starch and cellulose and used by plants as a structural building material. The Calvin Cycle takes molecules of carbon straight out of the air and turns them into plant matter. The carbon created in the Calvin Cycle is also used by plants and animals to make proteins, nucleic acids, lipids, and all other building blocks of life.

The Calvin Cycle has four main steps: carbon fixation, reduction phase, carbohydrate formation, and regeneration phase. This is where the energy to fuel chemical reactions in this sugar-generating process starts and is provided by ATP (adenosine triphosphate) and NADPH, (molecules). They are chemical compounds which contain the energy plants have captured from sunlight.

 


Figure 3: The Calvin cycle is a part of photosynthesis, the process plants and other autotrophs use to create nutrients from sunlight and carbon dioxide. The process was first identified by American biochemist Dr. Melvin Calvin in 1957.

 

Step 1: Carbon Fixation – is the method plants use to attach carbon dioxide from the atmosphere to a chemical called RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase) in order to start the process of photosynthesis.

Step 2: Reduction Phase – Second step in the Calvin Cycle of photosynthesis, where energy reacts with chemicals to create the simple sugar G3P.

Step 3: Carbohydrate Formation – Type of sugar that is an important nutrient for most organisms.

Step 4: Regeneration Phase – Fourth and final step in the Calvin Cycle of photosynthesis, where energy and sugar interact to form the molecule RuBP, allowing the cycle to start again.

 

So, what does all this mean to us Horticulturists? Do we try to grow more C4 and CAM plants for our changing climate? What will this mean for our everyday ‘popular’ C3 plants that we like to grow? If we adapt the plantings that we grow, will this benefit the Environment and the plantings will be more suited to our changing environment?

 

References:

Fig 1: https://evolution.berkeley.edu/evolibrary/search/imagedetail.php?id=369&topic_id=&keywords=
Fig 2: https://www.coursehero.com/sg/cell-biology/alternative-mechanisms-of-photosynthesis
Fig 3: https://www.nationalgeographic.org/media/calvincycle

 

  1. Anderson, E., Barthlott, W. and Brown, R., 2001. The Cactus Family. Portland: Timber Press.
  2. Bidlack, J. and Jansky, S., n.d. Introductory Plant Biology.
  3. Alternative Mechanisms of Photosynthesis – Course Hero. www.coursehero.com/sg/cell-biology/alternative-mechanisms-of-photosynthesis
  4. berkeley.edu. 2020. Stomata (1 Of 3) Function. evolution.berkeley.edu/evolibrary/search/imagedetail.
  5. Henry Shaw Cactus and Succulent Society. 2020. C3, C4, CAM Photosynthesis – Henry Shaw Cactus and Succulent Society.
  6. org/resources/digest/plant-info/c3-c4-cam/
  7. Ladiges, P., Evans, B., Saint, R. and Knox, B., n.d. Biology.
  8. Society, N., 2020. Calvin Cycle. National Geographic Society. www.nationalgeographic.org/media/calvincycle
Are Plants Social Creatures?

Are Plants Social Creatures?

Unremarkable and largely unnoticed by the many hikers that passed it on their way to higher peaks, there is a half-rotted remnant of a Kauri tree (Agathis australis) that fell to the earth decades ago in a New Zealand forest. Unnoticed, that is, until Professor Sebastian Leuzinger of the Auckland University of Technology passed by, and realised it was not dead at all.

This unassuming trunk has remained alive decades after it fell and Professor Leuzinger quickly found the live wood was functional and showed definite water flows. How could this be possible, when the stump had had no leaves and none of the normal equipment a tree would need to draw water through its stems and leaves?

This Kauri remained grafted and connected through its roots to other Kauri trees in the surrounding forest, whose own activity provided the water flows and nourishment the stump needed to remain alive. By supporting each other, these trees form a resilient colony that works together, genetically unique as individuals but linked together through the roots.

“This is different from how normal trees operate, where the water flow is driven by the water potential of the atmosphere,” Professor Leuzinger says. “The stump has to follow what the rest of the trees do because since it lacks transpiring leaves, it escapes the atmospheric pull.”

So are plants social creatures?

Social organisms are groups of individuals that form social structures to enhance their survival in the world – just as you and I live in societies and form communities to better specialise and provide mutual support in our lives.

There is increasing evidence that plants of all kinds do exactly this: working together to develop specialisations, mutualisms and cooperative structures that enhance their survival.


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The Hidden Lives of Trees

In Peter Wohlleben’s now-famous book, The Hidden Life Of Trees, it describes how umbrella thorn acacias react to feeding by giraffes. Very shortly after the trees detected feeding damage they produce a chemical that turns the leaves bitter and inedible, and the giraffes no longer find them palatable. However, this isn’t just in the trees the giraffes fed on – it influences the surrounding trees, up to about 100 metres away. These trees are communicating and it turns out the chemical exchange is through ethylene, the same gas that ripens your bananas and damages cut flowers.

Other plants can tell when insects have begun chewing on them, and mount a chemical communication that readies their neighbours for the coming attack. Research from ETH in Switzerland found that Brassicas infested with herbivore eggs induced a chemical response that caused surrounding brassicas to turn on their defence mechanisms, even before they had eggs on them. In turn, these plants produced more flowers and more seed much faster than they would have, as a proactive means of ensuring the transfer of their genes and ongoing survival.

This strategy of working together to share information and mount a defence is a clever evolutionary response to the enduring threats posed by insect damage and almost looks like an ‘arms race’ as insects and plants react and respond. Chemicals such as jasmonic acid influence the responses of surrounding plants and induce chemical or hormonal reactions that prepare their colleagues for an imminent attack.

 

 

Professor Stephan Mancuso is a scientist at the University of Florence who believes that the parts of a plant are, in effect, much like a giant brain. A plant needs to be able to communicate across its whole structure as well as through the environment that surrounds it, using a combination of electrical, biological, physical and chemical stimuli. This, he says, poses the question of awareness and consciousness in plants.

How aware are plants of their own existence?

“Consciousness is a little bit tricky in both our languages. Let’s talk about awareness. Plants are perfectly aware of themselves. A simple example is when one plant overshadows another – the shaded plant will grow faster to reach the light. But when you look into the crown of a tree, all the shoots are heavily shaded. They do not grow fast because they know that they are shaded by part of themselves. So they have a perfect image of themselves and of the outside,” says Professor Mancuso.

Mancuso says that plants are excellent at detecting vibrations, especially around the 200 to 300 hertz frequency because that is close to the vibrations that running water makes. This kind of stimulus-response helps the plant’s roots to orient toward the water source, hidden from light in the damp earth.

As horticulturists and plant professionals, we let the plants do the talking. But if you look a little closer, you may just find they are doing a lot more talking than any of us ever realised.

 

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Burning The Competition

Burning The Competition

By: Andrew Price FAIH RH0004 (Photos: Andrew Price)

Weed growth is a valuable indicator of the health of the landscape. Weeds tell you so much about the potential of the site and should be given your full attention.

In cultivation I get much joy from the “happy accidents” of a plant coming up in the perfect spot that makes my job so much easier, plus the client essentially gets a free plant. Unfortunately a majority of weed growth is unwanted and antagonistic to the cultivated garden, which is why weeding is such a necessary albeit overwhelming task.

Chemical control has so many biological drawbacks without even factoring in operator safety, plus you are left with the ugly dead shell of the weeds that need removal anyway.

I have been experimenting with weed burning for several years now and consider it the best method of control for a number of reasons:

  • Easily eradicates seed growth that would be impossible to remove without the patience of a saint.
  • There is nothing to remove from site except your memory of what was there.
  • The temperature removes the biological signature and seeds left by the weed residue allowing new species to establish.
  • Your hands stay clean and warm – great on a winter’s morning.
  • This makes weeding fun and quick not something that gets put in the too hard basket. An employee of mine had an apt saying “If it is fun it gets done”.
  • I regularly quote a line from Apocalypse Now when using this weed control method which is “Terminate with Extreme Prejudice”.

 

 

Now before you go setting your weeds ablaze and perhaps causing a runaway fire that will not look good on your CV, please consider that this is a skill that has to be done with thought, care and caution. This is not a job relegated to an employee that would be outwitted by a box of hammers.

Like anything that sounds too good to be true there are limitations to the effectiveness of this method, there are some species of weed that will need regular treatments before it gives up the fight – dandelions and onion weed are prime examples.

Species that it works best on are Flickweed/ Hairy Bittercress (Cardamine hirsuta), Spotted Spurge (Euphorbia maculata) and Winter Grass (Poa annua) – with a name like that it is no surprise that it hates being burnt. Interestingly Ficus species (F. macrophylla & rubiginosa) that come up in walls are easily killed plus wayward Ficus pumila shoots and stems are eliminated with extreme prejudice.

Another good trick is to pull the weed out by the roots if it is large or has the potential to regrow and burn the root stem or tuber, which gives most plants a death sentence. The trick is to get them when they are young as they are a smaller target. Larger weeds are normally slashed down with a whipper snipper then burnt at ground level; a repeat treatment a week later normally forces it off this mortal coil.

 

 

I hate clichés like the plague but one teaspoon of prevention is better than a pound of cure.

Be prepared to have your insurance updated by the good people of Fitzpatricks with a runaway fire clause listing the risk minimisation measures you have in place e.g. fire extinguisher on hand, site preparation, weather monitoring etc. Never use this method on dry windy days with a high fire risk!

Sweep paths and gravel of leaves to negate flare-up hazards, being especially careful with highly flammable leaves like Eucalyptus. Ensure that there has been no fuel or oil residue on paved areas.

Wet the soil and mulch before attempting to wilt weed growth and treat only in cool still conditions with watchful care of any ember activity. Be sure to go back over treated areas and check for any smoke activity. If in doubt use a pump sprayer to wet any spots that might reignite with a sudden gust of wind. If you are prepared and of sound mind you will find that the norm is a weed free garden and when they do gather the courage to germinate you almost pity their fate.

I have experimented with a variety of butane guns but my favourite is found in the tool section of Bunnings that will cost you $40 with enough change for a small chocolate bar.

Be safe and enjoy the smell of burning weeds in the morning!

 

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Curiosity: What Are Hedge Apples?

Curiosity: What Are Hedge Apples?

In Benalla, Victoria, a knowledgeable local horticulturist advised Angie Hamilton and Rupert de Crespigny that the unusual trees on their property were Hedge Apples (Maclura pomifera). After his advice that the trees were excellent for the skin, the couple recently commercialised their find into a unique, niche business based on the plants’ unique seed oils.

So what exactly are Hedge Apples?

It turns out they are species with a tremendously rich history and a unique ecology in their native habitat of North America. Also known as the Osage Orange, they are related to Mulberries (Moraceae) and derive their name from the Osage Native Americans. The trees produce wood that is highly-resistant to rot and makes excellent posts and timber with long-lasting durability, even being used to make wagon wheels and mine shaft timbers.

The wood has a beautiful deep orange hue and Native Americans searched far and wide for the wood to form bows which were strong, flexible and long-lasting. The wood and seeds are rich in pomiferin, a type of isoflavone that makes the wood useful as an insect repellent, antimicrobial and potentially with some anti-cancer properties.

As the Benalla couple attest, the plant’s oil is where the magic lies – its seeds are very high in both linoleic and oleic acids which have excellent wound-healing and skin hydration properties, albeit in tiny amounts. “It takes more than 100 kilograms of Hedge Apples to produce 200 millilitres of oil, but to exclusively produce such pure magic in Australia is worth the effort”, explained Rupert.

Osage Oranges in Early America

In 1804, the explorer William Dunbar travelled along the Mississippi River and sent cuttings to President Jefferson. Professor Jonathan Turner, who taught biology at Illinois College, also brought cuttings to the northern states. John Wright, editor of the publication ‘The Prairie Farmer’, championed the species as an excellent living fence due to its one-inch thorns and dense habit.

By the late 1840’s, Professor Turner believed that Osage Orange was the best available fencing material, describing it as “horse high, bull strong and pig tight” and it served as a “hedge” fence long before the invention of barbed wire.

By the 1850’s Osage Orange hedges made the fencing of entire farms possible. The French found the Osage Indians making bows from the wood and called it Bois d’Arc (meaning wood of the bow), which also gave rise to the common names Bodark and Bodarc. The species itself is named after William Maclure, a geologist, in his honour.

The story Liquid gold found on Benalla trees first appeared on Stock & Land.


 

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Assessing the Effectiveness of Urban Heat Reduction From Trees and Plants

Assessing the Effectiveness of Urban Heat Reduction From Trees and Plants

Many cities and regions across the world have now committed to expanded areas dedicated to greenspace to mitigate rising temperatures and the heat-trapping effects of the ‘urban heat island’.

The definitions of ‘increased urban green space’ include wider use of street trees, maintenance of remnant urban forests, green roofs and green walls, and other plantings that replace heat-absorbing surfaces such as concrete, glass and steel.

However, questions remain: how much area is needed to provide cooling? Which plants are most suited to reducing urban heat especially as both heating and moisture demands increase?

 

Some scientists have attempted to assess urban cooling by comparing the air temperature in parks with that of nearby streets, a simple measure that would assess an urban region side by side. One analysis from a range of other studies showed that there was comparatively little benefit, just 1.0 degree Celsius of cooling during the day and less at night (Bowler et al 2010) between parks and adjacent streets.

Two studies in Hong Kong and Manchester found that street trees offered greater cooling benefits than green roofs, and that mature street tree plantings with around five per cent density were sufficient to reduce the pavement temperature by one degree (and five per cent density from saplings was enough for half a degree reduction). As another point of comparison, replacing all vegetation with asphalt raised the surface temperature by 3.2 degrees Celsius, demonstrating the definite benefit from plantings (Skelhorn et al 2014).

Thermal image on the effects of trees on urban heat

Thermal image on the effects of trees on urban heat

Researchers at the University of Hull showed that the best measure of a tree’s ability to provide cooling could be determined by its water flow, which is measured using sap flow meters that assess evapotranspiration as water is moved from the roots to the leaves and outwards to the atmosphere.

A healthy, well-watered Callery Pear (Pyrus calleryana, a widely-used urban street tree in Australia and Europe) of around four metres in height could absorb around 60 per cent of the incoming solar radiation and offer a cooling benefit around six kilowatts (about the same as a mid-sized home air conditioning unit) (Ennos 2015).

Simple assessments of urban planting benefits provide mixed answers – the challenge for urban planners, landscape professionals and others in the quest for more greenspace is to account for the right area, type, selection and maintenance of urban greenspace that keeps its cooling benefits active and functioning.

This will require modelling and analysis across the engineering, urban planning, horticultural and other disciplines to provide a better assessment of the right planting mix for a given region.

References:

  • Bowler D, Buyung-Ali L, Knight T M and Pullin A S (2012), ‘Urban greening to cool towns and cities: A systematic review of the empirical evidence’, Landscape and Urban Planning, Volume 97, Issue 3, 15 September 2010, Pages 147-155.
  • Skelhorn C, Lindley S and Levermore G (2014), ‘The impact of vegetation types on air and surface temperatures in a temperate city: A fine scale assessment in Manchester, UK’, Landscape and Urban Planning, Volume 121, January 2014, Pages 129-140.
  • Ennos, R (2015), ‘Can trees really cool our cities down?’, accessed on 19 April 2020, <https://theconversation.com/can-trees-really-cool-our-cities-down-44099>

 

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.

Power Plants: Can Electricity Boost Crop Yields?

Power Plants: Can Electricity Boost Crop Yields?

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.

 

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Member Spotlight: Meet Christian Jenkins MAIH RH0157

Member Spotlight: Meet Christian Jenkins MAIH RH0157

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.

https://www.instagram.com/p/CAGc2DMF2H4/

 

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

 

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.

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

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

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.

 

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.