Information about plants & gardens for Brisbane & Qld
Welcome to Queensland's gateway to gardening - a collection of news, information, resources and ideas of interest to gardeners, especially residents of Queensland, Australia.
Get Results Gardening 16/08/19
TOP PLANTS: Introducing Salvias - Salvia species & hybrids
BASICS: What is Humus?
THE WORLD OF PLANTS: Inside Succulents
THIS WEEKEND: Neat Natives
Get Results Gardening is a weekly mini-magazine delivered via email. It offers high-quality gardening information for SE Qld while keeping the inexperienced and even the reluctant gardener in mind. Easy plants, timely tips, ideas, motivation. Get a 3 month free trial subscription. To receive the above edition in your inbox, email before 10am Friday 16/08/19.
Garden Events 2020
Organising a garden show, open garden or similar event in Qld in 2020? If you already have a date locked in, you can submit it NOW for inclusion in the Queensland Gardening Events Diary. You can send in additional details (key attractions, opening times, etc) closer to the event if you wish, but adding your date ASAP will give you more exposure to potential visitors and stallholders. Basic text listings (which do include a website link) are free. Featured listings are also available for a modest fee. Go to the Queensland Gardening Events Diary for more information.
From Drought to Dengue
The return of rainwater tanks to South East Queensland may also see the return of dengue fever, suggests a recently published study.
Temperatures in tanks and buckets were monitored at several sites across Brisbane through the 2014 winter. Then Aedes aegypti - a mosquito species responsible for transmitting dengue, Zika and other diseases - was cultured under similar conditions.
It was found that the insect was capable of completing its lifecycle through a Brisbane winter. Brisbane was previously considered too cool and dry to support Aedes aegypti year-round.
The revival in home water collection and storage means standing water persisting for at least 32 days is now common throughout the suburbs. The research showed that tanks or buckets could potentially breed the mosquitoes, tanks having advantages in terms of higher humidity and moderated temperatures in the air cavity.
Screening of tanks will be important to preventing future dengue outbreaks, but the researchers observed native mosquito species Aedes notoscriptus in "sealed" tanks throughout the winter. They suggest that water trapped in gutters and pipes (including first flush devices) could be the source.
Aided by rotting leaves, these reservoirs become infested with eggs and larvae that are washed into tanks with the next rainfall. Adults that develop are able to escape from even tiny gaps in screens or seals.
Aedes aegypti was common in Brisbane in the early decades of the twentieth century, probably due to the number of unsealed rainwater tanks and other storages. As these were phased out, the species largely disappeared from the region. Without rigorous maintenance of the twenty-first century's water harvesting systems, the mosquito and its diseases could again pose a significant threat.
The Garden Scene
More news about plants and gardens in Queensland, plus other useful and interesting horticultural news from around the world.
Look to the Trees
A recently published study conducted in Australia is in line with international research that a vegetated landscape is good for us. What's more, it indicates that the presence of trees is crucial. Data was collected from residents of Sydney, Wollongong and Newcastle aged over 45. It was found that 30% or more tree canopy cover in the district was associated with lower odds of psychological distress while but that an equivalent area of just grass actually increased them. Similar results were found with respect to self-reported feelings of general health. Low-lying vegetation did not seem to have much effect one way or another. Sources: Urban trees found to improve mental and general health, Association of Urban Green Space With Mental Health and General Health Among Adults in Australia. (July, 2019)
Age of Logan Resident Revealed
A blue gum (Eucalyptus tereticornis) already recognised as one of Logan's oldest trees has been scientifically dated to about 378 years old. Differences in resistance (indicating the rings) were measured by probing the trunk. The tree has now been officially named "Gandalf". It's located on private property at North Maclean. With the cooperation of other landholders, Logan City Council is hoping to expand its tree age testing program to catalogue historic trees throughout the city. Source: Logan’s Gandalf is a grand old tree (July, 2019)
Butt litter bad for plants
Surprisingly, the effects of discarded cigarette butts on terrestrial plant growth has not been studied until now. Recently released experimental results from the UK, however, have shown that they do indeed impact plants - and not in a good way. Germination success and subsequent growth of clover and ryegrass was found to be reduced by the presence of cigarette butts in the soil. It would appear that most of the damage was caused by the filters, regardless of whether the cigarette was smoked or not. It's thought that the cellulose acetate component and/or plasticising chemicals used in their manufacture caused the observed seedling inhibition. Source: Cigarette butts hamper plant growth - study (July, 2019)
Crave nature instead
Research has found that simply being able to see nature where you live reduces cravings for alcohol, cigarettes and junk food. This could be having access to a garden or even just good residential views, provided they comprise more than 25% green space. Source: Seeing greenery linked to less intense and frequent cravings, University of Plymouth (July, 2019)
Coping with cottonwoods
The vigour and dominating nature of coastal stalwart Hibiscus tiliaceus (cottonwood tree or cotton tree) has presented some management concerns for Sunshine Coast Regional Council. The based on results of a new report, Council is proposing a change of management at two pilot locations at Shelley Beach. This includes removal of some trees and pruning of others to reduce density and lift the canopies, improving visibility for the safety of people on foot (including those using the toilet block) and in cars. Trees removed will be replaced with other native species meeting the amenity requirements of these areas, which will also increase ecological diversity. Outcomes at these test locations will inform maintenance decisions elsewhere in the region. More information including full report is available from Sunshine Coast Regional Council here: Cottonwood tree study. (July, 2019)
Smelly sea breezes
Tweed Shire Council has been receiving complaints about foul odours from residents suspecting a sewage leak. Investigations have identified the culprits - fruiting mangrove trees. The grey mangrove (Avicennia marina) began fruiting prolifically a few weeks previously and the fallen fruits have been accumulating in parts of the estuary. The hydrogen sulphide gas produced as they decompose has the same "rotten egg" smell as sewage. The strength of the odour seems to depend on a combination of fruit quantity, weather conditions and tides. Source: Mangroves are the source of sewage-like smells in Tweed. (July, 2019)
Drought defeats garden competition
The Lockyer Valley Garden Competition, normally a part of the Laidley Spring Festival, has been put on hold because of the drought. Lockyer Valley Regional Council decided this was preferable to encouraging any unnecessary water use. However, residents can still register to open their gardens to the public during the Festival if they choose. More information here: Garden Comp on hold for 2019. (June, 2019)
New city hall a breath of fresh air
Sunshine Coast Regional Council has revealed designs for its proposed new City Hall. The landscaping will be an important part of the overall concept, incorporating balconies and rootop. Plant-covered arbours will shade outdoor dining areas in the precinct. All is designed to reflect region's native plants and terrain. Construction is expected to begin in 2020. Source: Local environment the inspiration for proposed City Hall design Sunshine Coast Regional Council (June, 2019)
Gympie gave macadamias to the world
New genetic research by the University of Queensland and Southern Cross University has tracked the origins of the first macadamias grown commercially (in Hawaii) to a small population at Mooloo, north-west of Gympie. It's even possible that the global macadamia industry that subsequently developed is based on seed collected from a single tree. This means there's still lots of potential for further improvement and adaptation of the crop through breeding, taking the advantage of genetic diversity in native populations. Source: Gympie identified as birthplace of global macadamia industry (May, 2019)
Sunshine Coast verge gardens
The Sunshine Coast Regional Council have made it easier for residents to establish verge gardens with an amendment to the local law. Provided gardens conform to self-assessable criteria, planting can occur without having to submit an application or get public liability insurance. The criteria include rules about plant heights, setbacks and access requirements. Any plants installed must be on the associated road verge planting list. Note that gardens containing plants not on the approved list or that fall outside the self-assessable criteria in any other way will still need a permit. For more information, go to sunshinecoast.qld.gov.au/Environment/Trees-Plants-and-Gardens/Plant-a-verge-garden at the Sunshine Coast Regional Council website. (May, 2019)
A new analysis of US data has shown that even quite short periods of moderate physical activity - which includes gardening - could improve health. Just 10-59 minutes per week was associated with a 18% lower risk of death from any cause, compared to people who were inactive. More time or more vigorous activity had even better effects. Source: Even low levels of leisure time physical activity lowers risk of death In another study published in the same month, a 14% reduction in risk of death was observed among low-activity participants who replaced 30 minutes of sitting time per day with light physical activity.Source: Replacing Sitting Time with Physical Activity Associated with Lower Risk of Death Mar 25, 2019 (March, 2019)
North Stradbroke Island preserves rainfall record
Paper-bark tea tree leaves preserved in Swallow Lagoon on North Stradbroke Island have been used to investigate south-east Queensland's weather over the last 7000 years. Using variation in carbon isotope composition, moisture stress experienced by then-growing leaves can be determined. The period 5000 to 6000 years ago was found to be wet, but more variable and increasingly dry about 3000 years ago. Severe droughts during this phase suggests that the probability of something worse than the 1997-2009 Millennium Drought occurring in the future may be higher than the one in 10,000 years currently predicted. It also appears that Queensland was colonised at the end of an unusually wet period, The Little Ice Age (about 1450 to 1850). Source: Preserved leaves reveal 7000 years of rainfall and drought (February, 2019)
Platypuses in the Albert
Following a reported sighting in 2017, environmental DNA (eDNA) samples were taken from Logan City's Albert River during last year's breeding season. This has established the presence of animals in two sites at Wolffdene and one at Cedar Creek. Small amounts of platypus DNA were found at four other sites. The exact locations will remain secret. Source: Science confirms platypus living in Logan’s Albert River(March 2019)
As a part of their "Our Natural City" strategy, Gold Coast City Council has recently launched an initiative to help native bees. It's proposed that owners of properties over 1200m2 could be subsidised to purchase native bee hives. There may also be an opportunity to work with local bee experts, although hives only need maintenance every 12-18 months or so. Stingless bee keeping workshops offered as part of the City's NaturallyGC program are another way for residents to learn about native bees. Source: Native bees have Gold Coast Mayor buzzing (March 2019)
Brisbane community composting expands
Brisbane's 20th community composting hub has recently opened in association with the Graceville Community Garden. Instead of sending kitchen scraps and green waste to landfill, participating residents can take it to a composting hub to be turned into something useful. Source: Sustainability growing through community composting (February, 2019)
Work at Eumundi Conservation Park has recently improved a poorly drained section to allow its whole network of trails to be enjoyed in all weather. Source: Source: Eumundi Conservation Park trail network complete (March, 2019). In Brisbane, the Summit Track in the Mt Coot-tha precinct is about to get an upgrade, too. Erosion cause by high foot traffic and water runoff will be addressed with resurfacing plus new handrails. A new trail from the Brisbane Botanic Gardens to the Mt Coot-tha Summit is expected to open later this year. Source: Mt Coot-tha precinct upgrade delivers better trails (February, 2019)
Cities scale up pest attack
Recent research recording the incidence in several American cities of a debilitating scale on a species of maple tree predicted larger insect populations in the warmer south than the cooler north. Instead, they found the amount of impervious concrete and asphalt in the vicinity of the tree was more strongly correlated with infestation levels than temperature. Source: Dying Trees in Cities? Blame It on the Concrete (March, 2019)
Gympie's strategy for pandandus dieback
Gympie Regional Council have just announced their Leaf Hopper Integrated Pest Management Strategy, which will combine leaf stripping (to stop associated rot from spreading) and biocontrol with a parasitic wasp. Transplanting from areas where there is an abundance of young plants available will be done and a propagation program from collected seed is planned, too. Source: Council to protect Rainbow's Pandanus Palms, Gympie Regional Council.
A flying visit
If you live on the Sunshine Coast, you may get a chance to see little red flying-foxes (Pteropus scapulatus) visiting the area over the next few weeks. These nomadic bats travel to the coast from the north and west to feed from (and pollinate) eucalypts and other native trees. It's expected that drought conditions in western Queensland will bring more than usual this year. The little reds are said to be noisier than the black and grey-headed flying-foxes, but are expected to head back again by late March. Source: Little red flying foresters seeking Sunshine Coast blossoms, Sunshine Coast Regional Council (February, 2019)
New IndigiScapes nursery opens, main centre closes as upgrade continues
Opening of the new native plant nursery at Redlands IndigiScapes Centre marks completion of the first stage of a five-year upgrade of the Capalaba facility. From 28th January, the main centre building, car park and some bush trails will close for the next stage, which includes expansion of the cafe and other facilities. More information about the upgrade and facilities available while work is in progress can be found at the Redlands IndigiScapes Centre website: www.indigiscapes.com.au (January, 2019)
Gardens a haven for pollinators
Pollinating insects are vital to natural ecosystems, agriculture and even backyard fruit and vegetable production. Maintaining pollinator populations when they're under pressure in so many ways has been a matter much discussed in recent years. A new British study looking at city-wide urban land use has found that residential gardens and community gardens (allotments) could make a significant contribution to pollinator conservation. High income households were associated with more pollinators in their gardens than low income, reflecting a greater abundance of flowering plants on average. Meanwhile, parks and public spaces were found to be poor pollinator habitats. They usually contain few flowers, not even weeds. Source: Cities could play a key role in pollinator conservation. Full study: A systems approach reveals urban pollinator hotspots and conservation opportunities (January 2019)
Not everyone loves street trees
Between 2011 and 2014, nearly a quarter of eligible residents in Detroit (USA) submitted no-tree requests and researchers decided to find out why. Economic problems resulted in big cuts to the city's maintenance budget. The large numbers of dead and hazardous trees consequently left untended contributed to urban blight. This made residents wary of new trees and the authorities planting them. Residents feared they would be left with responsibility for caring for trees and wanted a greater say in which trees were planted. Education, choice and communication were seen as a way forward. Read more: Why People Reject City Trees, University of Vermont (January, 2019)
Vale David Austin
Many readers will know of David Austin, or have encountered his world famous roses. Mr Austin passed away on 19 December 2018, aged 92. His breeding work brought the beauty and fragrance of historic roses to new varieties better suited to the demands of modern gardeners, including repeat-flowering, disease resistance and colour range.
Hands off houseplants
Research led by La Trobe University in Australia has found that you'll help your houseplants with a "look but don't touch" approach. The slightest touch from an animal, insect or even other plants activates a huge number of defensive genes, which consumes energy. If the touch is repeated enough, growth is reduced. Source: Plants don't like touch, new study finds, La Trobe University. (December, 2018)
Unfortunately, a few plants won't make an as great a difference to indoor air quality you might hope. appreciable difference in normal home or office situations. However, scientists in America have modified a plant with a mammalian gene to extract chloroform and benzene from the atmosphere. The protein produced breaks down chloroform into carbon dioxide and chloride ions and benzene into phenol, all of which can be used within plants and actually help them grow. The subject in this experiment was pothos (Epipremnum aureum), a common houseplant. Source: Researchers develop a new houseplant that can clean your home's air, University of Washington. (December, 2018)
Future power plants actual plants
A team of scientists working in Italy have demonstrated the potential to use plants to harvest wind energy for electricity generation. The natural structure of leaves was found to convert mechanical force applied at the surface into electrical charge, which is then transferred through the plant in living tissues. By modifying a tree with artificial leaves that touch the natural leaves when blown by wind, electricity was generated. This could be harvested by what amounts to plugging into the plant. A whole tree or even a whole forest could potentially be turned into a power plant. Source: IIT researchers show how plants can generate electricity to power LED light bulbs. (December, 2018)
Dollar value of botanic gardens
Deloitte Access Economics has recently studied the Royal Botanic Gardens & Domain Trust in NSW to quantify the value its gardens return to the people of that state. The Trust oversees three gardens and a parkland in the Sydney region. These contributed about $140 million to the NSW economy in the 2016-2017 financial year. The majority of this was attributed to interstate and international tourism. The value delivered to NSW residents in terms of social/cultural benefits was estimated at $186 million per year. The three gardens directly employ the equivalent of 231 full-time employees, but the number of jobs created when suppliers and tourism were included was estimated at 1,116. That is, for every person employed full time, more than three full time jobs (or the equivalent) are indirectly created in other sectors. The full report can be downloaded from rbgsyd.nsw.gov.au/stories/2018/more-than-just-parks-and-gardens (October, 2018)
Recently released results of a psychological study suggest greener neighborhoods may improve children's brains. 11-year-olds living in urban areas of England were assessed. Even after allowing for socio-economic factors associated with neighbourhoods, more greenspace was correlated with better spatial working memory. This cognitive function records and processes information about an individual's surroundings and is related to attention control. It's also correlated with academic achievement. While this study couldn't prove that the environment directly caused the better memory performance, it points the way to further research and another possible benefit of more parks and gardens in cities. Source: Greener neighborhoods may be good for children's brains. Full report: The role of neighbourhood greenspace in children's spatial working memory (September, 2018)
Some older news items of continuing interest have been moved to appropriate subject pages. Check the Guide to Pages or use the search function at the top of the page. Older news about the health and social benefits will be collected in a new page: Effect of gardens & gardening on human health.