Saturday, 30 July 2016

Common Coral Tree - Weeds

Erythrina indica, Erythrina crista galli and Erythrina x sykesii

Common names: Indian coral tree, Thorny coral tree, or Cockspur coral tree

This tree is quite eye-catching with its beautiful bright red flower heads. From personal experience it really 'took our eye' when we first moved to the Coffs Coast when we saw it in flower (I even took photos so it could be identified!). 

Originating from northern Argentina, eastern Brazil, Bolivia, Paraguay and Uruguay the Coral tree was originally sold as a fast growing, beautiful ornamental tree. Coral trees have become an invasive pest plant in native bushland areas. It has a broadly spreading habit and will grow up to 6m or more tall. Its stems are sparsely covered in sharp thorns and the leaves are divided into three elongated leaflets. 

The flowers which appear before the leaves in spring, are scarlet red to dark red pea-shaped and are borne in large elongated clusters at the tips of the branches. The seed pods are also elongated, dark brown and are slightly constricted between each of the shiny mottled seeds.

The common coral tree has been spread from garden and street plantings and become an environmental weed in the coastal regions of NSW including the Coffs Coast. It has also recently become naturalised in south-eastern Queensland, and is a potential or emerging environmental weed in that region. 

Coral trees can be spread by seed (except for the hybrid Erythrina x sykesii) and propagates freely vegetatively, via stem segments and suckers. The branches are very brittle and break easily so logs, branches, and even twigs will grow into new plants.  However, it has to be said that the spread of the common coral tree is often aided by the dumping of garden waste in bushland areas.

It is primarily a problem along creeks and rivers, but will also grow in disturbed natural vegetation and open woodlands. If you travel further north from the Coffs Coast, keep an eye out (especially when it is in flower) and you will see many trees growing in the Byron hinterland, where it has become a very serious problem.

Eradication? Small plants may be pulled by hand however take care to remove all roots before bagging and disposing. Stem inject larger plants with 100% glyphosate by using the drill method rather than hatchet as the stem has a very high water content. Because stems re-grow so readily when in contact with the soil, Coral trees are very difficult to control, so it is paramount that all plant material is removed from the site. Use protective clothing and gloves when dealing with this tree as the thorns can cause injury, which can then become infected. 

For something that is just so pleasing to the eye it sure packs a punch!

Thursday, 28 July 2016

Pest Alert for Lilly Pilly Hedges

Looks a pretty 'cool' beetle with its glossy pale green colour? Well think again folks, this little critter can completely decimate your Lilly Pilly (Syzygium) hedge. If your hedge is looking a bit like the following image ....... read on for the bad news.

For some time the green strip leaf beetle Calomela pallida was thought to be the culprit for the edges of Syzygium leaves being chewed which gave the hedge a sparse, lacy appearance. However, Dr Chris Reid, an Entomologist and Leaf Beetle expert at the Australian Museum in Sydney correctly identified Paropsides calypso was to blame. 

This 9mm, bright green beetle is an Australian native beetle from northern NSW but can now be found from the tip of Queensland all the way into Victoria - mainly due to the popularity of Lilly Pilly hedges and poor quarantine between nurseries. It has taken from 5-10 years for the beetle to spread such a huge distance.

Its eggs are laid on leaves or leaf buds, and the green larvae are relatively solitary (not clustering) during feeding. Paropsides calypso pupates in the soil and both beetles and larvae feed on Syzygium leaves. The larvae is quite large - around 2cm, pale green, glossy and a bit like a curl grub stretched out (quite chubby).

As this pest has only recently been identified as being a huge problem, there is not a lot of information on just how best to be rid of it. If you are lucky enough to have chooks a sweep along the hedge might knock the larvae to the ground and the 'girls' can forage for the juicy larvae, also as they pupate in the ground the chooks might be able to scratch them out too. Neem oil has been found to be effective but one has to be quite diligent to get good spray coverage on the hedge. There was a post written earlier this year about Diatomaceous Earth - this might be worth a go too - to see this article please click here.

Mealy bug infested Agapanthus
Growing plants as a monoculture can be a problem as it has been found that one by one the world's most toughest garden plants are succumbing to newly-discovered, debilitating pests and diseases - take for instance the Elm, Ash, Buxus, Roses, Agapanthus, Impatiens, Clivea etc etc - the list goes on.

Every time we plant a hedge, or a single-species border or a sweep of identical perennials, we can spread and encourage either existing or future pestilence. Just figure, the pathogens that are attacking these mass-planting favourites aren't usually unknown (as is the case with Paropsides calypso) however when we start to supply them with unlimited food all conveniently co-located, they can rage out of control. With so much food on hand they can quickly multiply and spread rapidly, the plant species affected doesn't have time (through seed-grown generational development) to generate resistance. 

Monoculture planting is not a modern design element in gardens - Boxwood (buxus) hedges, for instance have been used for hundreds of years in formal gardens. Its use has been popular because it can be shaped to produce intricate topiary and have a dramatic effect in very formal arrangements like knot gardens. Design elements with grouped swathes or hedges of single plants to provide harmony and unity within a garden space have always held sway in garden design.

Why do we grow hedges? Is it for privacy, as a boundary marker, to keep intruders out, as a windbreak, as a way of creating special spaces within a garden, or as a feature? ........ most hedges would be grown for more than one of these purposes. 

Perhaps a sure fire way of preventing the spread of these modern day pests is to have diversity in our plant selections in our gardens. If privacy is the main driver for a hedge and space allows, an informal, or natural hedge could be worth a thought. The disadvantage of course, is that there is not the actual 'formality' of a hedge. On the flip side though, a natural hedge of mixed plantings will only require light pruning from time to time and provide a wonderful soft backdrop in your garden. Of course, the excellent added bonus would be encouraging a diverse cross section of fauna to your garden to assist with management of pests!

Further reading can be seen at Derek J. Whitten's blog.

Friday, 22 July 2016

Citrus Pruning Advice from Phil Dudman

Photo Natsky

Phil Dudman (pictured above) is undoubtedly one our region's best known horticultural journalists. Phil's 2013 article from 'ABC Organic Gardener'  (see here for article) addresses the subject of pruning citrus. Phil gives some really, really good advice that is relevant for the Coffs Coast and is well worth reading.

At our last meeting a member asked about pruning citrus and mentioned that there is conflicting advice on whether to prune or not to prune..... Phil basically says it's fine NOT to prune however it is perfectly fine to prune too and gives good advice on how to prune citrus - from young trees to what looks like a hopeless case. 

  • When to prune;
  • Pruning an established tree;
  • Pruning for health (citrus wasp gall);
  • Training a young citrus tree;
  • Reviving a neglected tree; and
  • Importantly - tool hygiene.

If you need information on any of the above please visit this link for Phil's article.

Tuesday, 19 July 2016

Growing Rosellas

How about this advice for when to plant Rosella seed from GardenDrum's Arno King?

"I sow seeds directly in the vegetable patch in my subtropical garden when the coconut oil in my kitchen goes from a solid to a liquid – generally around early August (February in the northern hemisphere). In warmer areas sowing would be earlier, while in warm temperate areas sowing would be later, generally around September (March in the northern hemisphere)."

To see more on this article titled 'Jam of the Tropics, Growing and Using Rosella' please head to this link.

Recently a member asked about growing Rosellas on the Coffs Coast, I have never grown them (just know that ants really adore their fruit) so this article fits the bill perfectly. 

Sunday, 17 July 2016

Gavin's Sub-Tropical Plant - Zebra Plant

President's Message - July 2016

'Windarra', Gumble

It was unfortunate our guest speaker for this month was unable to join us, because her talk was to have been about how to prevent back injury and pain when gardening.  This was a topic I was certainly looking forward to hearing about given my personal experience with a troublesome back. 

Gardening can indeed cause us some health difficulties, but it can also have a really positive impact on our physical, mental and emotional well-being.  In fact, I’m sure the health benefits of gardening far outweigh any risk of injury we might have when we’re out there working in our gardens. 

For example, gardening provides us with a work-out for our respiratory and cardiovascular systems and can improve strength, endurance and flexibility, as well as helping to prevent problems such as heart disease, diabetes, obesity and osteoporosis.  Isn’t it great that we don’t have to spend precious time at the gym or competing in triathlons when doing something in our garden is a really great way to get some healthy exercise.

A quick look at the internet tells me that gardening activity has the benefit of releasing endorphins, which work to alleviate stress.  Studies have also shown that spending time in a garden can help lower blood pressure, stimulate the appetite and foster a good night's sleep.

But beyond the physical benefits, there are many other benefits to be had from gardening.  For example, gardening can help with the development of social and intellectual skills, including those needed for social inclusion or rehabilitation.  In addition, a garden can provide an oasis of calm and somewhere peaceful to escape to, helping restore a sense of balance and wellbeing.  And a healthier diet can be a fantastic by-product of gardening.

So the next time you’re out in your garden, why not take a minute to think about how much all that hard work you’re doing produces not just a lovely garden, but also a healthier and happier you.  

Sunday, 10 July 2016

Honeysuckle - Japanese (Weeds)

Lonicera japonica

Originating in China and Japan this robust climbing or scrambling shrub to 8 m high is another garden escapee. It suckers and can form large mats on the ground and huge masses in the canopy of trees. It smothers trees and shrubs and can restrict sap flow in the soft barked plants it grows around. It can also cause premature deterioration of fences and buildings.

Stems tend to be purplish and hairy when young, becoming woody with flaky bark on mature stems. Leaves are bright green and hairless except for hugging hairs along veins and margins. The white, ageing cream to yellow coloured flowers are in pairs near the branch tips, flowering from Autumn to spring. Flowers have a strong, sweet scent. The fruit is a shiny black berry. Both leaves and berries are toxic.

Dispersal is mostly by seed, however it tends to spread more through branches taking root when contacting the ground. Dumped garden waste and contaminated soil contribute to its distribution too. Strangely enough it is still widely available at markets, fetes and nurseries, despite it being a documented weed on the Coffs Coast.

Control is by digging it out - plant and all roots. This method reduces site disturbance and allows more specific selection of species as opposed to spraying. Ensure that as much of the root system is removed to reduce the amount of regrowth.

The cut & paint method can also be used where the vines are cut off at ground level and again about a metre high and immediately painting both ends of the stem with undiluted  product. This is useful for larger plants which cannot be easily removed by hand.

Friday, 8 July 2016

It was Engraved Glass and a Vast Garden for us Today!

Today was one of those days that makes us all feel so smug that we live on the Coffs Coast - it was a stunning day and to boot, it was spent with a great group of CHGC members.

Studio 101 at Sandy Beach was where we all met up - there were some folk who gathered at the Botanic Garden for a quick cuppa before heading north but the rest of us live up this way so we all met up at the studio.

Faye Thomson and Member Sue
Faye Thomson is an accomplished Australian artist and glass engraver. Faye has always had an interest in art and design but it wasn't until the 1980's that she discovered her true passion was in engraving glass. 

Anne Dybka, a very well known glass engraver who had a studio at the Rocks in Sydney tutored Faye on the basic mechanics and principles of engraving. 

Being such a skilled craftswoman she has designed and hand engraved stunning unique designs (inspired by Australian flora and fauna) which have been sold both domestically and internationally.

This piece (left) really took the eye of member Gavin because? yes, it was titled 'In the Rainforest' he could even name the species depicted!

Faye works on only quality glass vessels, so mainly uses European glass for her engravings. As all her work is unique each design is signed by her. 

We are just so fortunate to have such a very, very talented person living on our doorstep. Faye reluctantly (because they are so much a part of her), sells her work from her studio in Sandy Beach. A terrific first stop on our outing and thanks for sharing your passion Faye.

On to Peg Wilmott's garden in Woolgoolga - this garden has been Reserve Champion in the CHGC Spring Garden Competition THREE times and Peg has also taken out awards for the over 75 years of age gardener too.

Peg is a true 'green thumb' and her love of plants shines through in this very large town block with a steep slope to the rear.

The front of Peg's home faces to the north so is a very hot space and she has excellently dedicated this area to her succulent and cacti collection (which is vast). 

Due to the height of many trees and shrubs Peg has created micro climates that are just perfect for her many camellias and azaleas.

It doesn't seem to matter when this garden is visited there is always colour that will catch the eye.

This garden is so vast we were all able to wander at whim and not encounter anyone else...... amazing!

Peg is a very generous hostess and looks after the many visitors to her garden - including the birds, which give her much joy. See this wonderful bird feeder construction right.

One of Peg's visitors

There are literally hundreds and hundreds of pots in this garden, to water them all must be a real challenge.
Thanks to the Program Committee for organising the day and my thanks to member Michael Reid who provided the images for this post.

Monday, 4 July 2016


Do you have fresh conical shaped holes with little piles of dirt either in your lawn or garden in the morning? You, my friends have most probably got bandicoot(s) visiting overnight.

The bandicoot has a long tail and long nose and prefers to hang out at night-time similarly to a rat but that is where their similarities end.

Bandicoots eat spiders, cockroaches, and a variety of other insects, snails and most importantly their favourite food - the black beetle and beetle larva known as curl grubs. These grubs feed on the root systems of your lawn causing dieback or brown patches.  Bandicoots are effectively also aerating your lawn so that it will grow with renewed vigour during spring. They cause no long-term damage and are beneficial to lawns and gardens. Once their food source has gone, so do they - move on from your yard. What perhaps is less attractive is, they can dig up seedlings in the vegetable patch. If you are living in a bandicoot area perhaps some mesh to protect your precious seedlings might be the way to go.

These marsupials breed year-round but have a breeding peak from winter to summer, so look out for them now as they will be more active and may have babies with them. Bandicoots generally live for 2-4 years in the wild. They are territorial and usually solitary. The female stays in a relatively small area to forage and mate, but males have a bigger territory and mark and defend their territory by fighting off other males. They do this by standing on their back legs and clawing at each other's shoulders and backs, often leaving scars. 

Bandicoots are multi-oestrus, meaning they breed several times during the year. Females can give birth to as many as five babies, but usually only one or two survive. These babies remain in her pouch for about three months until they're old enough to fend for themselves. Their gestation period is very short, about 11 days (the shortest of any marsupial). The young are born very tiny and under-developed. They travel through a cord attached to their mother's womb to reach the pouch and here they drink milk from the mother's teats and grow until they are large enough to leave the pouch.

Bandicoots are usually solitary animals however during breeding times, your backyard can become a temporary boxing ring for their territorial scuffles. 

Like wombats, bandicoots have backward-facing pouches so when mum is digging around, her pouch won't fill up with soil. 

Your best bet to observe them is by torchlight either at night or in the early morning when they will often still be out and about foraging for food.

Bandicoots have at least four distinct volalisations:

  1. A high-pitched, bird-like noise, used to locate one another;
  2. When irritated, they will make a 'wuff, wuff' noise;
  3. When feeling threatened or alarmed, they will make a loud 'chuff, chuff' noise and loud whistling squeak at the same time;
  4. When in pain or experiencing fear, they make a loud shriek.
During the day bandicoots will nest in shallow holes in the ground, lined with leaf litter and built under dense vegetation or debris, hiding them from predators and protecting them from rain and sun.  

Northern brown bandicoot (isoodon macrourus) is around 30-47cm in size and weighs up to 2.1kg. It has small, rounded ears, an elongated snout, and a speckled brown-black coat with a pale to white underbelly.

Saturday, 2 July 2016

Rose Pruning

The purpose of rose pruning is to create stronger and healthier bushes. With the Coffs Coast climate it mainly provides roses time to rest and recover along with tidying up the older wood within the bush - unlike colder climates where pruning is necessary to protect them from harsh weather conditions.

It is extremely important to remember that most rose advice is written for Mediterranean and cold climates. A general rule of thumb for the Coffs Coast is to prune on the last weekend in July which is the 8th week of winter. However, if you wish to have a flower flush at a certain time (or occasion), this will determine just when you should prune your bushes. To obtain this flush, prune 75 to 80 days prior to the event for floribundas, minifloras and minis and 60 days ahead for hybrid teas and shrub roses. Spring flowering roses (those that do not repeat flower) are pruned after they have flowered in late spring.

One thing to remember is that during summer it is best not to hard prune your roses as this can lead to sunburn on your plants, which in severe cases can result in plant death. You might like to do a prune in the first two weeks of autumn after most of the heat has passed. This will be really only a long deadheading of flower stems rather than a 'prune' per se. This is beneficial as it will bring a new flush in autumn for the last hurrah blooms of the season. 

Roses need to be monitored closely to remove any weakened or non-producing stems. Remove blind shoots from the bush unless they are thick as a pencil in which case they can be pruned to a fresh side bud along the stem. A new flower shoot will grow from this bud. You will see very useful illustrations of pruning in this Pruning Guide PDF - just increase the size so you can see the diagrams clearly.

As with all pruning tasks around the garden it is imperative that you have your equipment scrupulously clean and SHARP! Use bypass secateurs where the cutting blade moves past a fixed bar. Anvil style secateurs where the blade closes against a flat surface can leave bruises on the stems and introduce infections. A pull saw and loppers for cutting large canes will assist for better leverage and for cutting thick branches. Obviously, protection from rose prickles for yourself is necessary too.  

For a month by month 'to do' list please see this link from the NSW Rose Society. Yates have some excellent advice on pruning roses and this can be seen here.

Friday, 1 July 2016

The Calyx and the Royal Botanic Garden, Sydney

The Royal Botanic Garden Sydney is turning 200 this year.

Botanic Garden's farm cove before the seawall was constructed (pre 1864)

Some brief details about the early years:
The garden was founded by Governor Macquarie in 1816 as part of the Governor's Domain and is the oldest botanic garden in Australia. The entire site is 64 hectares which includes the Domain (34 hectares). Being a botanic garden it supports a huge number of plant species (8,900) and also houses in the Herbarium some 1.2 million specimens. Much of the groundwork for the success of the gardens is attributed to Charles Moore, who was the Director of the gardens for 48 years. He vigorously tackled the problems of poor soil, inadequate water and shortage of funds to develop much of the Gardens as we see them today. He is also responsible for the Palm Grove at the heart of the Garden and is an excellent reminder of his skill and foresight.

In 1879 a substantial area of the Domain (south of the Conservatorium of Music) was used for the building of the Garden Exhibition Palace which was constructed for the Sydney International Exhibition. Built of wood with towers and turrets around a giant dome (30m) in diameter surmounted by a lantern 64 metres above the ground and was constructed in just eight months! This building had a footprint equal to 180 tennis courts! It rather resembled a cathedral in shape and London's Crystal Palace in design and covered two hectares. After the exhibition it held a lot of government records and Aboriginal art work. 
Unfortunately the building and its contents were completely gutted by fire in the early morning of 22 September 1882 and the land, now known as the Palace Garden, was added to the Botanic Garden. 

As part of the celebration for its 200 year history the Botanic Garden opened a new attraction called The Calyx. This new addition is integrating the Arc glasshouse (completed 1987), however the pyramid glass house (opened 1972) has been demolished to make way for this new addition.

The name 'Calyx' refers to the whorl of sepals that protect a developing flower bud and the steel frames radiating from the centre creating a doughnut-shaped building is representational of that. The area in the centre of this area is ringed by a mirror pond, with a raised area in the centre which can be used for exhibitions etc. 

Currently this space is taken up with some mondo-covered sculptures of howler monkeys.

The inside space of the Calyx is just stunning. It houses the largest interior continuous green wall in the Southern hemisphere. This living wall is 51 metres long and 6 metres high and features a staggering 18,000 individually potted plants including curly parsley, alternantheras and heucheras thriving in their vertical home. 
Misting water can be seen at the top of the six metre living wall

Each morning Horticulturalists tend to the wall before it opens maintaining and replacing any plants that need it. Each plant is in an individual pot so pots are easily exchanged.
This wall is intentionally designed for ALL visitors, including children who might want to crush the leaves of a chocolate mint to smell the aroma. 

The maintenance of this wall is supported by a high tech production house which has three chambers - each with different climates where exotic and native plants are grown for the Calyx.
This mural is made up of Lindt cholates

Adjacent to the wall is the first feature exhibition 'Sweet Addiction: The Botanic Story of Chocolate' where you can taste, touch, see, hear and smell all things CHOCOLATE! This exhibition traces the story of chocolate from bean to bar and centres on a miniature Amazonian rainforest with cocao trees, vanilla orchids and flamingo flowers.
And there are interactive exhibitions and video installations that touch on the ecological issues surrounding chocolate production.

For further reading and more images check out this link from green magazine, a publication for inspirational stories on sustainable design.

The Sydney Morning Herald have done a wonderful article and you can see it at this link about the history of the gardens.

Colvillea - Colvillea racemose

Flower of the Month - July 2016

Also known as Colville's Glory Tree, Whip Tree and Racehorse Tree. With long dense clusters of brilliant orange pea shaped flowers resembling a horse's mane, this tree has a magnificent crown with fern-like foliage not unlike a Poinciana (to which it is related).

A native of Madagascar, it is an erect tree, often with a long trunk and spreading branches. It has fern-like, pinnate leaves to a metre long, with many small, elliptic to oblong leaflets. In southern warm temperate climates it will be deciduous but further north it will retain its foliage.

From late autumn to winter, this tree turns on a spectacular floral display that rivals other world-renowned flowering species like the Illawarra Flame Tree, Jacaranda or Poinciana, and it is a remarkable sight to see in full flower. It bears scarlet to orange flowers in racemes to 30cm in length. Its grape-like clusters of velvety buds can range from chameleon green to blood orange.

This is a fabulous tree when in bloom and very delicate and lacy looking in leaf. It can grow to a height of 8 to 16 metres. Because it is a tropical tree with the same range and climatic tolerances as Poinciana it prefers moderately fertile, moist but well-drained soil in full sun. It likes to be grown rather dry in the winter but lots of water in summer - so is perfect for the Coffs Coast.