News and Events

Botanical Buzz - Lilly Pilly

Wednesday, May 21, 2014

The beautiful tough lilly pilly is an important botanical element in the Dubbo Regional Botanic Garden.

There are roughly fifty different varieties of lilly pilly grown in Australia. They all belong to the genus Syzygium in the myrtle family, Myrtaceae.

Lilly pillies are drought tolerant evergreen rainforest trees and are cousins to the historically and economically important Syzygium aromaticum from which the spice, cloves are harvested.

They may be grown in full sun or partial shade and have attractive glossy green foliage.

There are two species of lilly pilly in the Dubbo Regional Botanic Garden, Syzygium australe and Syzygium paniculatum and both are native to Australia.

Syzygium australe, which incidentally is the floral emblem of Coffs Harbour, is grown in Shoyoen and a dwarf cultivar of the species is grown in the Sensory Gardens. It can grow to 35m tall but responds well to pruning to produce an attractive dense compact shape. It is used as a hedging plant near the beautiful sandstone gecko in the Sensory Gardens and may also be found in the refined and elegant outer roji of the Japanese Tea House.

The magenta lilly pilly, Syzygium paniculatum has been planted in the Oasis Valley as part of a suite of Australian dry rainforest plants. It grows to a height of 15 m with a trunk diameter up to 35 cm.

Both the Syzygium australe and Syzygium paniculatum produce attractive edible fruits which may be eaten fresh or cooked. The fruit can be used to make jams and jellies.  Autumn visitors to the Dubbo Regional Botanic Garden will be able to spot the fluffy white flowers and small magenta fruits on the Syzygium australe.

                                                                                                                    By Ian McAlister & Karen Hagan

Botanical Buzz - Triadica sebifera - Chinese Tallow Tree

Thursday, May 01, 2014

Shoyoen in the Dubbo Regional Botanic Garden is glowing with autumn colour.

A deciduous tree that will make a spectacular contribution to the autumnal display in the next couple of weeks is Triadica sebifera, formerly known as Sapium sebiferum, and commonly known as the Chinese Tallow Tree. It belongs to the Euphorbiaceae family and is native to eastern Asia.

Triadica sebifera is legendary for the vibrant yellow, orange, red and purple of its heart-shaped leaves during autumn.

It is a fast growing small to medium sized tree with a domed canopy. It is disease and pest resistant, and once established, it is also drought tolerant. The plant sap and leaves are toxic. 

Sebifera and sebiferum mean "wax-bearing" and refer to the vegetable tallow that coats the seeds. In China and Japan the tree was once cultivated for its seeds. The seeds were thrown into boiling water to remove the wax, which was skimmed off and used to make candles. They were then pressed to extract oil for use in lamps, as a purgative, and for making oil-paper and soap.

It is said to be the third most productive vegetable oil producing crop in the world, after algae and palm oil. This makes it an attractive plant for biodiesel production. Just one mature tree can produce 100,000 seeds every year and a mature stand can produce 4,500 kg of seeds per hectare per year.

However, Triadica sebifera’s robust characteristics and prolific production of viable seeds contribute to its highly invasive nature. The trees at Shoyoen are managed to reduce the likelihood of Triadica sebifera spreading and growing where it is unwanted.

Autumn is regarded as a prime time to visit Japanese gardens and visitation is expected to rise at Shoyoen as people come to enjoy the colour, peacefulness and harmony of this special garden.
                                                                                                                      By Ian McAlister & Karen Hagan


Botanical Buzz - Groundcovers

Friday, April 04, 2014

A garden design that flows and guides the eye from one feature to the next is both calming and beautiful to behold. Shoyoen and the Sensory Gardens at the Dubbo Regional Botanic Garden both soothe and restore the spirit in this manner.

Groundcovers play an important part in unifying a garden. They can also surprise and delight by providing a swathe of colour in a shaded area and reduce maintenance by keeping weeds down.

Trachelospermum jasminoides 'Tricolor' always catches  visitor’s eyes as they stroll through the sheltered walkway between Shoyoen and the Sensory Gardens. It has covered the ground with delicate mottled and variegated leaves of white, pink and green.

Trachelospermum  is a genus of about 15 species of evergreen woody vines in the dogbane family Apocynaceae. All species are native to southern and eastern Asia except for one. Trachelospermum comes from the Greek, literally meaning "neck seed", and referring to the seed shape.

Another groundcover used to great effect in Shoyoen is Juniperus horizontalis “Blue Forest”.  The distinctive dense, steely blue foliage is very attractive. The scale-like green leaves turn a dull purple in winter.

The genus Juniperus  (Juniper) belongs to the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50 and 67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the mountains of Central America.

Specimens belonging to the genus Juniperus are amongst the oldest trees in the world.  A Juniperus occidentalis in Sierra Nevada, California, United States has been estimated as being 2,200 years old.

Juniper chinensis (Chinese Juniper), a cultivar of which may also be found in Shoyoen is one of the most popular species for use in bonsai. It is also a symbol of longevity, strength, athleticism, and fertility.
                                                                                                                       By Ian McAlister & Karen Hagan

Botanical Buzz - Mexican Sage – Sensory Garden

Wednesday, April 02, 2014

French Lavender (Lavandula dentata), Buddleia (Buddleja davidii 'Harlequin') and Mexican Sage (Salvia leucantha) are presently filling the Sensory Gardens at the Dubbo Regional Botanic Garden with rich purple flowers.

Coincidentally purple is an important colour during the Christian festival of Lent  (5 March – 17 April).  Purple is associated with mourning and so anticipates the pain and suffering of the crucifixion. It is also the colour associated with royalty, and celebrates Christ's resurrection and sovereignty.

The most striking of the purple flowers in the Sensory Gardens are those belonging to the Mexican Sage, a herbaceous perennial that is native to subtropical and tropical conifer forests in central and eastern Mexico.  The arching velvety purple clusters of flowers set against its soft mid-green leaves are very attractive.

Salvia is the largest genus of plants in the mint family, Lamiaceae, with nearly 1000 species of shrubs, herbaceous perennials, and annuals. The name Salvia derives from the Latin salvere ("to feel well and healthy, health, heal"), the verb related to salus (health, well-being, prosperity or salvation); referring to the herb's healing properties. Pliny the Elder (AD 23 – August 25, AD 79), a Roman philosopher was the first author known to describe a plant called "Salvia". It is likely that he was referring to Common or Garden Sage (Salvia officinalis). Common Sage has a long history of culinary and medicinal use.

Another eye-catching plant in the Sensory Gardens is the Japanese Blood Grass (Imperata cylindrica 'Rubra’). The leaves of this unusual and dramatic grass are green at the base with red tips that almost appear to glow. It has been used as a highly effective and attractive edging near the pond.

The plants in the Sensory Gardens have been carefully chosen to ensure that the garden is full of colour throughout the winter months.

                                                                                                         By Ian McAlister & Karen Hagan

Botanical Buzz - Demonstration vegetable garden – Dubbo Regional Botanic Garden

Wednesday, April 02, 2014

On the southern boundary of Oasis Valley is a special place, often overlooked by visitors to the Dubbo Regional Botanic Garden, a demonstration organic vegetable garden.

It is a place that never fails to invoke the curiosity of young visitors. Many youngsters are unfamiliar with the natural habitat of their daily veggies. Their eyes light up as they spot beans, eggplants and sweet corn. They laugh with delight when a bit of supervised pulling is rewarded by a wonderful carrot!

Many people enjoy gardening but it is particularly important to children. During gardening children develop a love of nature, an understanding of science and learn the delights of eating fresh food. It is also a physical activity which entices them away from electronic gadgetry, and teaches them cause and effect and problem solving, in a real world context.

The demonstration vegetable garden is a living seasonal guide and source of encouragement for new gardeners. There is a varied selection of vegetables growing in the garden at the moment including eggplant, sweet corn, beans, pak choy and carrots. Cabbage and beetroot seedlings have just been planted.

It is looked after entirely by volunteers – Friends of the Dubbo Regional Botanic Garden – who delight in sharing their love of gardening with others.

If you are interested in volunteering the odd half hour to tend and water the garden, and generally help maintain this important and flourishing resource, please contact Dubbo City Council’s Community Participation Facilitator Kath Oke 6801 4000.

                                                                                                                       By Ian McAlister & Karen Hagan

Botanical Buzz - Companion Plants

Tuesday, March 18, 2014

A local plant species renowned for its grace and resilience has been selected as a companion plant for some delicate beauties due to arrive at the Dubbo Regional Botanic Garden later this year.

The Acacia pendula (Weeping Myall - wattle) belongs to the sub-family Mimosoideae of the family Fabaceae. It grows to roughly 10-12m high and has a graceful, weeping habit. Its striking blue-grey foliage makes it an attractive ornamental plant.

The Acacia pendula is tough and long lived. It can tolerate heavy soils and waterlogged sites but it is also highly drought tolerant. There are excellent examples of Acacia pendula in the Biodiversity Garden and one at the north east corner of Elizabeth Park next to the mosaic.

Eleven Acacia pendulas will be planted just outside the fence on the west side of Shoyoen. They will provide shelter for new cherry trees. Three Prunus × yedoensis (the Tokyo Cherry) will be planted in Shoyoen later this year, after the Acacia pendulas have become established.

This is not the first time that wattles have been used to provide shelter for more delicate plants in the Dubbo Regional Botanic Garden. The Dubbo Christian School planted 200 local wattles in the Oasis Valley to protect the rainforest species until they became established. This has been very successful.

Globally, companion planting for pest control, pollination, shelter, providing habitat for beneficial creatures and maximizing use of space, has been practised in one form or another, for thousands of years.

One of the best ways of keeping a garden healthy is to make sure that it is as bio-diverse as possible.  A broad selection of companion plants which ensure the availability of flowers all year will attract birds, pollinating insects (like butterflies, bees, and native wasps), reptiles, beetles and all sorts of helpful garden buddies.
                                                                                                                           By Ian McAlister & Karen Hagan

Botanical Buzz - Fruit Trees in the Dubbo Regional Botanic Garden

Friday, March 14, 2014

One of the unexpected delights of the Dubbo Regional Botanic Garden is the fruit produced in the garden.

The fruit trees in the Sensory Garden include three varieties of apple tree (Gala, Orange Pippin and Pink Lady) in addition to lemon, mulberry, kumquat and pomegranate trees. Birds were quick to feast upon the apples but there are still plenty of lemons and kumquats, and some beautiful pomegranates to be spotted.

The fruit trees were included in the Sensory Garden to provide a feast for all the senses. Their inclusion also supports the movement in schools to encourage children to grow their own food and eat healthily.

The fruit trees in the Sensory Garden remind young people that fruit grows on trees not on supermarket shelves!

In Shoyoen the persimmon tree is attracting everybody’s attention. The abundant fruits are turning orange and providing an unrivalled autumn display.  The botanic name of the persimmon is Diospyros kaki, which means 'food of the gods' and has its origins in ancient China.

The persimmon tree was planted in Shoyoen as a special reference to our Sister City Minokamo with whom Dubbo will be celebrating the 25th Anniversary of the Sister City relationship, later this year.

Dojo Hachiya-gaki,  dried persimmon have been a speciality of Minokamo for hundreds of years and are internationally famous. They are considered as being suitable gifts for royalty. Producing perfect, traditionally dried persimmons is very labour intensive and they are very expensive.

Persimmons have been grown in Australia for almost 150 years but they are not common because most people are only familiar with the astringent varieties. Astringent persimmons can only be eaten when they're completely ripe and squishy-soft, otherwise the bitter tannins make them taste horrid. The sweet variety of persimmon was introduced in the late 1970s.

Autumn makes a visit to the Dubbo Regional Botanic Garden particularly fruitful.
                                                                                                                                By Ian McAlister & Karen Hagan

Botanical Buzz - Roses

Thursday, March 13, 2014

Roses have a long and colourful history. They have been symbols of love, beauty, secrecy and war.

The rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. The majority originated in Asia and a few in temperate zones such as North America and Europe. The genus is, according to fossil evidence, 35 million years old.

Roses can be erect, climbing or trailing, and often have stems armed with sharp prickles. Flowers vary widely in colour, size and shape, and are usually large and showy.

Roses have been cultivated for thousands of years. Paintings of roses have been discovered in Egyptian pyramid tombs from the 14th century BC. Records exist of them being grown in Chinese gardens and Greek gardens from at least 500 BC.

The rose has been associated with secrecy since ancient times. Conversations taking place under a real or an image of the rose were considered “sub rosa” – confidential. Five-petalled roses were often carved on Christian confessionals, indicating that the conversations would remain secret.

During the fifteenth century, the rose was used as a symbol for the factions fighting to control England. The white rose symbolised York, and the red rose symbolised Lancaster, as a result, the conflict became known as the "War of the Roses." The Tudor Rose is a combination of the two roses, symbolising reconciliation between the two warring families.

It wasn't until the late eighteenth century that cultivated roses were introduced into Europe from China. Most modern-day roses can be traced back to this ancestry.

In the Sensory Garden of the Dubbo Regional Botanic Garden the climbing rose, Rosa 'Pierre de Ronsard' covers the white arbour in glory while the beautiful white (Glamis Castle) and red (William Shakespeare)  David  Austin roses fill the walled garden with their heavenly scent.
                                                                                                                                                                          Ian McAlister and Karen Hagan

Botanical Buzz - Phytoremediation – the cleaning power of plants

Thursday, March 13, 2014

Clean Up Australia Day Sunday 2nd March is approaching fast so it is an opportune time to describe how plants can help clean up contaminated soil and water.

Phytoremediation from the Ancient Greek phyto, meaning "plant", and Latin remedium, meaning "restoring balance", describes the many processes by  which plants can be used to reduce pollutant concentrations in contaminated soils, water, or air.

Plants can take up, store, transform and degrade pollutants including metals, pesticides, macro-nutrients, solvents, crude oil and even explosives.

It is a slow and complex process but it can be a cost effective and environmentally friendly alternative to more radical options such as excavating contaminated soil and disposing of it elsewhere.

Arsenic contamination is a serious global issue. Overtime, sunflowers (Helianthus annuus) can help reduce arsenic contamination by absorbing it and concentrating it in their tissues.

Some contaminants can be inactivated or degraded by the plant’s metabolism.  It has been reported that Bull Rushes (Typha sp.) can effectively remove TNT from contaminated water in this manner.

Sometimes it is not the plants themselves but the organisms that live in and on their roots, and in the surrounding soil which remove the contaminants. Microbial processes can lead to nitrogenous pollutants from fertilisers and other sources, being converted to nitrogen gas and released to the atmosphere.

Plants which have taken up contaminants need to be harvested and disposed of appropriately to avoid re-contamination.

Phytoremediation is used in the Sensory Garden, the Biodiversity Garden and the Oasis Valley, where carefully selected species of wetland plants help keep the water bodies clean. On a larger scale, Egret Park Wetland (an artificial wetland) uses wetland plants as one of the major methods of cleansing polluted urban stormwater runoff from the Keswick Estate before the water is allowed to reach the Macquarie River.

Team up with the plants on Clean Up Australia Day and make a positive difference.  
                                                                                                                             By Ian McAlister and Karen Hagan

Botanical Buzz - Silver Perch (Bidyanus bidyanus)

Friday, February 14, 2014

Visitors with sharp eyes will enjoy trying to spot the young Silver Perch (Bidyanus bidyanus) in the watercourse of the Oasis Valley, Dubbo Regional Botanic Garden. The attractive fish are well camouflaged against the pebbles on the river bed. Counting them as they slip in and out of the shadows – now three fish – now eight - is a simple almost meditative pleasure.

Silver Perch are native to the Murray-Darling river system. They were once widespread and abundant but their numbers have seriously declined. This is due to a number of factors including habitat degradation and competition from introduced species such as carp and redfin.

Silver perch are listed as a vulnerable species in NSW and it is illegal to take them from the rivers or streams in the Murray-Darling Basin. The fish in the Oasis Valley were supplied when they were fingerlings by a reputable fish farm.

Silver perch are omnivorous, feeding on small aquatic insects, molluscs, earthworms and green algae. Adults usually reach 30-40cm and 0.5-1.5 kg.

Care was taken to establish a good habitat for the fish before they were released into the flowing waters of the Oasis Valley.  A carefully chosen selection of native reeds and rushes were planted by local community groups last year, to cleanse and oxygenate the water.

A variety of snags (wooden logs) have been provided for the young fish to take refuge amongst, when threatened by visiting cormorants and herons.

The preparations have paid off. The young fish seem to be thriving. They have more than doubled in size since their introduction to the Oasis Valley watercourse late last year.

Silver Perch were chosen for the Oasis Valley to raise awareness of the need to look after our natural waterways and to give visitors, particularly youngsters an opportunity to observe a beautiful fish which has become less common in its native habitat.

                                                                                                                               By Ian McAlister & Karen Hagan