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Message in a bottleSpacer

The following have been selected from the questions received on the ASGAP World Wide web site over the past few months. You're welcome to comment on any issue concerning Australian native plants....growing, propagating or appreciating (even loathing!) ... anything.

If necessary, bung a message in a bottle if your net connection goes down!!


Westringia "Smoky"

Hello - I have an assignment to do on Westringia 'Smoky' and I am finding it hard to find information on it, in particular a botanical descriptor. I was wondering if you could help me out with this in anyway or point me in the right direction to a site on the net or a book that may contain such info?

Melbourne, Victoria

I don't know where you would find a botanical descriptor for this cultivar. It isn't a PBR variety so I doubt that anyone has done one. You might be able to get a botanical descriptor of the actual species (Westringia fruticosa) through a state herbarium or the Australian National Botanic Gardens.

A search in "Google" turned up a few brief items, the best of which is here - but it's probably not a great deal of help for your purposes.


Callistemon Presentation

Callistemon phoeniceus  
Callistemon phoeniceus
'Pink Ice'

Click for larger image

I am doing a Horticulture course and have to write a 3000 word essay on callistemons but am having trouble finding the right kind of information that I need. I also have to give a presentation to the class on this subject. If you could help me in any way it would be much appreciated.

Melbourne, Victoria

The Callistemon Page on our website might help. It contains information on propagation, cultivation, details (including photos) of selected species and cultivars, botanical relationships, history of Callistemon cultivation and references.


Natural Oils in Australian Flora

Hi. I'm trying to find out as much as I can about the chemical make up of the oils found in Australian flora. Can you help me?


As a matter of fact, I can....

Try the article "Australian Plants and Essential Oils" from the December 1998 issue of Australian Plants online. The article examines some aromatic families and genera and tries to pin down the active ingredients and how they smell to us.


Identifying Callistemon viminalis

  Callistemon seed pods
  Most callistemons retain the seed in the capsules for many years

I have what I think is a Callistemon viminalis. It's about 4 years old and just under 3 metres tall. Unfortunately, it's such a straggly, weedy looking specimen it's almost impossible to tell if it has a weeping habit or not. The very sparse flowers are indeed quite red but apart from that, I just don't know. Is their some definitive feature of flower, leaf or bark that might help me identify this tree once and for all?


There's no really obvious feature - botanists will have no problem because the arrangement of the anther filaments of the flowers is distinctive but this is not much help for the non-scientist.

Perhaps the only feature that may help is that C.viminalis tends not to retain the seed in the capsules after flowering. This is in contrast to most other bottlebrushes which form woody seed capsules along the branches which will retain the seed for many years.


Banksia - a Danger to Foundations?

I was reading information on your web site regarding Banksia ilicifolia.

We have a very tall one, about 15 metres high, on the other side of our fence and close to our house. We were just wondering if this tree has a destructive root system that might upset our foundations in any way. We are not in dispute with our neighbour - they would like to know the same thing. If you could possibly help with a short reply it would be much appreciated.

Western Australia

It's difficult to give a definitive answer as I'm on the east coast and have no direct experience with this plant. All I can do is try to relate eastern Banksia species of a similar size, to your situation.

On this basis, I would be very surprised if the plant had any effect on the foundations. Banksias are not generally noted for having an overly vigorous root system. Having said that, the roots could be a problem if there are underground drainage pipes - but any medium to large plant can be a problem if underground pipes are in the vicinity.

If you are really concerned, you probably need to talk to the local forestry department.


Problems with Geraldton Wax

Chamelaucium uncinatum 'Pink'
Chamelaucium uncinatum
Click for a larger image

I have a Geraldton Wax that's been in the ground for about a month now and sadly the bottom needles are starting to turn yellow. Is this serious and, if so, what can I do apart from calling the nursery to claim my 6 month warranty?


Well it may or may not be serious - Geraldton Wax tend to lose the lower leaves as they develop a trunk. It's probably a bit early to make a claim on the warranty.

I'm not really familiar with the climate and soils in your area but I would have thought that Townsville would be a very marginal climate for Geraldton Wax. They are native to areas of Western Australia with dry summers and probably are not going to be happy in the tropics (even Sydney is a difficult climate for them).

At this stage there's probably not much you can do but "wait and see".


Regeneration after Fire

I was just wondering about the bottlebrush, eucalyptus, paperbark tree, grevillea and the tea tree - how do they germinate or survive after a bush fire?

S B Australia

Well - I wish the answer could be as short as the question!!

Eucalypt regeneration  
Regeneration from the root stock of a small eucalypt after a fire  

These plants have a variety of ways to regenerate after bushfires. Some regenerate solely from seed while others are also able to re-sprout from the branches or roots.

Seed regenerators - these are often "pioneer" species that appear quickly after a fire. They may be fairly short-lived but help to stabilize the bare soil and restore lost nutrients by "fixing" nitrogen from tjhe atmosphere. The seed of these species may lie in the soil for many years before the heat of the fire cracks their hard seed coats and allows germination. Such plants include the many pea floerered species (eg. Pultenaea and Dillwynia) and the wattles (Acacia). Alternatively, the seed may be kept on the plant in woody capsules which open to release the seed when the plant is killed by the fire (eg. some banksias). Other seed regenerators are often found in moist forests where bushfire might be a relatively infrequent event. For example the mountain ash (Eucalyptus regnans) of Victoria and Tasmania relies on seed for regeneration and is killed by fire.

Re-sprouters - these are the most obvious plants after a fire as the masses of green shoots appearing from the burnt trunk or root stock are in sharp contrast to the blackness of the burst forest. Many bottlebrushes, paperbarks eucalypts and banksias are in this category.

This is just a brief explanation - there are a whole host of survival techniques developed by plants in response to environmental conditions. There is also some useful information on this topic in the article "The Passage of Fire"


Pruning a Wattle

We have weeping sticky wattle which needs a good pruning as it is getting too big for the area. The last owners planted it to close to the drive way. It would be a shame to have to chop it down as it is a talking point for people walking past. I have tried to prune it before with not much success.


I'm not sure what species you have but wattles generally don't respond well to severe pruning, unlike other plants such as bottlebrushes. Generally you need to make sure that you don't cut back into bare wood - there should be some green foliage below the points that you cut.

If you are in an area subject to frost, it would be best to wait until after winter.


Natural Distribution of Sugargums

I am trying to find out relevant information in regard to sugargums.

I was told they are a native to Western Australia but we have a pocket of them here in Victoria. Any information would be greatly appreciated as we need this info as a matter of urgency as the trees are under threat from development.


I'm always a bit wary about providing information on the basis of a common name. Because common names vary from place to place, it's often difficult to be sure about the real identity of the plant.

However, to the best of my knowledge Eucalyptus cladocalyx is the only eucalypt known as "sugar gum" so, I'm assuming that this is the species you are referring to.

E.cladocalyx is native to South Australia. None of my references refer to it occurring naturally in either Western Australia or Victoria. If you are confident about the identity of the plants, then they have most likely been planted (it is a widely planted species).

If you are sure that they are not part of a plantation, then it could be a new record for the species - to confirm this you would need to get in touch with the Melbourne Botanic Gardens so they can investigate.


Information on Native Frangipani

Hymenosporum flavum  
Hymenosporum flavum
Click for larger image

I have been unable to recover any information on the 'Native Frangipani' tree. I live in Mandurah West Australia and would like to establish if this - and the 'Jakaranda ' would be at all suitable for my front garden.

Western Australia

You will find some information on native frangipani (Hymenosporum flavum) on our web site. Although it's a rainforest species native to eastern New South Wales and Queensland, it is adaptable in many areas provided water is available.

Unfortunately I can't assist with Jacaranda. It grows well in many areas of eastern Australia but I have no detailed information on it as it isn't a native Australian species.


Adapting to Drought

I am a year twelve biology student. I have received an assignment in which I must perform a first hand investigation to gather information about structures in plants that assist in the conservation of water and describe adaptations of a range of terrestrial Australian Native Plants that assist in minimising water loss. This must be performed in my local area.

I am greatly interested in this topic, but lack the resources needed to perform the investigation on my own. I require a lot of help by way of brochures, information and general information on the topic.

If you could help me in this task, it would be much appreciated.

Gosford, New South Wales

Unfortunately I don't think I can be a great deal of direct help as this Society is mainly interested in the cultivation and propagation of Australian native plants. Although many of our individual members would have an interest in ecology, this is not the main focus of the Society and we don't have pamphlets and brochures on those issues.

However, after trawling around the internet for a while, I found a few links that might help. They aren't specific to the Central Coast but the adaptations described should still be relevant.

I hope this helps.


Propagating "Rose of the West"

  Eucalyptus macrocarpa - fruit
  Fruit of Eucalyptus macrocarpa (left)
Click for larger image

Hi, I have a couple of "Rose of the West" (Eucalyptus macrocarpa) growing in the paddock at they have flowers and pods on them, I would like to know how to propagate them. What stage do I pick the pods and identify the seeds inside.

Narromine, New South Wales

The seed in the pods should be mature within about 3-6 months of the flowers finishing. If you pick the mature pods, the capsules will open within a week or two to release the seeds.

There are guidelines on propagation on our web site. Take a look at:


Ailing Grass Tree

I wonder if you can help?

We planted a Xanthorrhoea in our courtyard about 4 years ago, digging a good diameter and depth hole and filling it with a sandy, well drained soil mixture. The trunk is about 0.5 m high.

It flowered almost immediately, and flourished up until about 6 months ago. Now instead of having a good thick head of green leaves, they are gradually yellowing and dying off. We do not use any fertilizers, except applying castings and water from our worm farm.

There has been mulch around the base, and we have an automatic watering system which applies a small amount each day. The ground around the base is moist.

Do you think it is getting too much water? Any other suggestions?

Any help you can offer would be appreciated before it's too late!


I doubt that there has been too much water but you could try cutting it back so there are some successive days when it gets no water at all. In nature, the plant would be subject to alternating wetting and drying periods so maybe that would help.

I would also stop applying the water and castings from the worm farm as these may be high in nutrients and that could be a problem. These plants generally occur naturally in nutrient poor soils and are adapted to that type of environment. It simply might be getting too much of a good thing!

Apart from that I can only suggest that you talk to the experts at the National Botanic Gardens. The Gardens are a great resource for the people of Canberra and if they don't have an answer, no one will!


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Australian Plants online - December 2002
Association of Societies for Growing Australian Plants