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Calyx Horticultural Services presents

Into Horticulture

Issue 7  ~  April 2012

Plant & Garden News

New Brunfelsia species a history maker
The requirement by the scientific community that new plant species be formally described in Latin has recently been dropped, with English descriptions now acceptable. This has paved the way for inclusion of DNA analysis to help distinguish the new species from close relatives. Brunfelsia plowmaniana, is the "first English-language diagnosis of a new species that relies exclusively on DNA data". DNA barcodes are likely to become more common in describing and identifying plants. Source: Plant DNA speaks English, identifies new species (March 2012)

Poorly made biochar not beneficial
Biochar is becoming so popular worldwide that many people are now trying to make their own at home. A study at Rice University, USA, has found that the expected beneficial effects depends on how the charcoal is produced. The study found that unless heated to at least 450C it could repel water and be less stable as a long-term carbon store, whether made from tree leaves, corn stalks or wood chips. Source: Cooking better biochar: Study improves recipe for soil additive (March 2012)

Blood oranges a breeding challenge
The specific cold period required to induce the blood oranges of Sicily to develop their red colour means they can't be reliably produced in many other citrus-growing regions. Scientists have identified the gene involved and analysed similar varieties from around the world, but it appears that developing new cold-independent blood oranges will be difficult through conventional breeding. They are now looking at genetic engineering. The anthocyanin pigmentation of blood oranges is desirable not only for its aesthetic qualities, but for the beneficial effects on human health. Source: New research could make it easier to grow health-promoting blood oranges (March 2012)

Palm Valley not a Gondwana relic
New analysis of central Australia's Palm Valley palms suggests that they aren't the remains of a prehistoric rainforest, but that seeds were brought from the north by Aboriginal people as recently as 15,000 years ago. More at the University of Tasmania website: Humans may explain the enigma of outback palms (March 2012)

Pests invade from dumped waste
A new infestation of yellow crazy ants has been found near a World Heritage listed rainforest in north Qld. Biosecurity Queensland believe that illegally dumped green waste was the cause: New infestation of yellow crazy ants at Mt Peter (March 2012)

Plants alive after 30,000 year freeze
Using tissue culture, whole plants have been regenerated from fruit buried by an Arctic squirrel in Siberian permafrost 30,000 years ago. It's believed that the squirrels' burrows aided preservation of the Silene stenophylla material, freezing it quickly and preventing thawing prior to discovery. These deposits may be a source of ancient germplasm of other plants for future research. Abstract of the Proceedings of the National Academy of Sciences paper here: Regeneration of whole fertile plants from 30,000-y-old fruit tissue buried in Siberian permafrost. See also Ancient fertile plants brought back to life from Siberian permafrost. (February 2012)

Weed saves bluetongues
Bluetongue lizards that feed on cane toads can be killed by their toxin, but it has been found that some populations are resistant. It appears that the invasive weed mother-of-millions, which they also eat, has an almost identical toxin. This drove natural selection for toxin-tolerance in areas where the weed grows. Source: Invasive plant protects Australian lizards from invasive toad: Study (February 2012)

Horticultural history revealed in ancient Persian garden
The remains of a lavish garden have been uncovered on the site of Ramat Rahel, an ancient palace near Jerusalem. Its advanced irrigation system meant a wide variety of plants could be cultivated with collected rainwater alone. It has also allowed researchers to discover which species were grown. Pollen isolated from the site's soil is not preserved well enough, but grains trapped in the wet plaster used to repair the irrigation channels and pools during their working life can be identified. In addition to common local plants, many exotic species were found in the 400-500 year old plaster. They were probably imported by the Persian rulers from throughout the empire as a display of wealth and power. Eventually, the garden will be recreated for modern-day visitors. Read more at the American Friends of Tel Aviv University website: Fossilized Pollen Unlocks Secrets of Ancient Royal Garden (February 2012)

2011 a good year for UK garden industry
Sales figures in the UK indicate that interest in "grow your own" (GYO) remained strong in 2011. While tomatoes continue to be the most popular crop, increases in other lines suggest existing gardeners are further developing their interest. Results for the garden and nursery industry overall were up in 2011 and garden retailers there are "cautiously optimistic" in spite of the general economic outlook. Source: Positive year end for the garden market and good prospects for grow your own (February 2012)

PlantBank to preserve Australian biodiversity
Australia is to have its own major seed repository, with ground broken on PlantBank at the Australian Botanic Garden, Mount Annan (NSW). In addition to storage of seed or live material - the ultimate goal is to bank every Australian species - research and public education will also take place at the facility. One of Australia's most important banks will store life itself (January 2012)

A new role for lignin
Lignin is a component of the walls of many plant cells, and is a waste product of paper and biofuel production. A surprising use has been identified - as a sustainable and non-toxic stabilising agent for unpaved roads. Read more at the Kansas State University website: The path less traveled: Research is driving solutions to improve unpaved roads (January 2012)

Editorial - Propagating good news

"Growing gardening" has been discussed in previous newsletters (Nos 2 & 3), and the issues of media coverage of gardening and of advertising and marketing for horticultural businesses were raised.

Often, I hear about a new plant, product, award or other piece of news in another media outlet, but in seeking more information find that the relevant website (e.g. business, professional association, amateur society) has not been updated.

Not only does this disappoint and frustrate individuals who might try to follow up on such reports directly (and thus potentially lose sales), but it hampers further coverage on other websites, blogs, social media, traditional media and newsletters like this one. That includes those valuable links to your own website.

Assuming you're able to make simple updates and upload media releases and fact sheets yourself (if having a website designed, be sure to ask about that), it's free publicity for you and your industry.

If you're responsible for your organisation's public relations, why not propagate your good news and help grow gardening?

Mothers Day in the Garden

Of all the gift-giving dates on the calender, Mothers Day (Sunday 13th May, 2012) is perhaps the one with the most potential for garden-themed gifts. Garden books, ladies' tools, hats and gloves, pretty pots - you'll find plenty to choose from in a good garden centre.

If you're taking Mum out for the day, many garden centres also have cafés for a relaxed lunch. The guest of honour can then choose her own gift from the range of plants and accessories on offer.

Alternatively, consider a garden show or open garden (if you live in Qld, check

Don't forget that the contribution of a few hours of hard labour in the garden will also be appreciated!
Examples of triple grafted trees, with graft points marked in white. Top: One bud has grown and been cut back while waiting for the others to shoot. Below: It can take some time and management for all buds to reach a balanced stage, which contributes to the cost of a good multigraft
Feature Article

Multigrafted Fruit - A Cocktail on a Tree

Eila and Jean, Noosa Jem, Queensland

Multi-grafted fruit trees are fun and unusual. They're also practical, being great time, space, and water savers.

Noosa Jem specialises in multi-grafted "Citrus Cocktail" trees. The dwarfing root stocks used are resistant to many common citrus diseases and have the ability to tolerate wet and cold conditions. Dwarf trees produce good crops of normal size fruit on a tree of manageable height. They can be planted either in the ground, or in large pots.

The most common misconception about multi-grafts is that they don't work because one of the varieties will "take over". This can be true if the plant is left to its own devices. The solution is simple and easy - prune back the more vigorous graft until the other(s) have caught up.

Of course, it's important to start with a well-produced tree with strong, stable and balanced growth.

You could have an orange tree with three different varieties that fruit at different times, giving a longer harvest period and avoiding a glut. Or, you could have a tree which produces limes and tangelos at the same time!

The creative gardener, or one with a small balcony space or limited space along a fence, could espalier a multi-graft with different varieties trained to grow in different directions.

If you want to grow a wide variety of fruit but have limited space or you just like to try something unusual, a dwarfing multi grafted tree could be for you.

For more information on Noosa Jem's "Citrus Cocktail" muligrafted trees, visit

The Virtual Garden Tourist

While not exactly the same as being there, it's possible to explore many great gardens of the world and catch up with international trends at garden shows by paying a virtual visit through your computer monitor. Avoid the airports, cost and crowds by checking out the following websites.

Chelsea Flower Show 2012: The world's most celebrated garden event will be on again from 22th to 26th May and is usually extensively covered online. Try:
RHS Chelsea Flower Show Official website
Chelsea Flower Show 2012 The Telegraph, UK
The RHS Chelsea Flower Show at the BBC website

Floriade 2012: This World Horticultural Expo, which is held in the Netherlands only once every 10 years, is running from 5th April to 7th October in 2012. Take a look at the online gallery:
Floriade 2012

If you want to pursue additional information and pictures about these events, just use your favourite search engine because they're likely to be covered on many other news sites and personal blogs. The garden designers or sponsors of individual displays might have more on their own corporate website, too.

The Science of Horticulture


We tend to consider water loss from plants as a bad thing, especially when we're trying to keep them alive during a drought. In the discussion of stomates last time, however, it was suggested that release of water vapour through them wasn't completely detrimental.

So, how can this process - transpiration - help the average plant?

Water transport: Water travels over distance in the pipe-like xylem tissues of stems and leaf veins, but normal capillary action is not sufficient to take it to the top of a tall tree. Water evaporating from the leaf creates a suction-like force which helps draw water up from the roots. As water is pulled from the root, the resultant differential (along with other root processes) in turn helps draw water from the soil.

Nutrient uptake and distribution: Some plant nutrients are able to enter the root and be carried to aerial plants parts in the transpiration stream.

Temperature regulation: Evaporation from the leaf cools it, which helps prevent damage and facilitate cellular processes under high ambient temperatures.

Transpiration is a part of plants' adaptation to a life on land. The significance of the above processes again demonstrate the importance of an adequate water supply (and healthy, well-developed roots) to achieving vigorous growth and maximum crop yields.

Further reading:
Transpiration University of Hawai`i at Manoa
Plants in Action  An online plant physiology textbook available at the University of Queensland website. Published by the Australian Society of Plant Scientists, New Zealand Society of Plant Biologists, and New Zealand Institute of Agricultural and Horticultural Science

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