[Front Page] [Features] [Departments] [Society Home] [Subscribe]

Australian Plants online

Electronic Mailbox

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!!


Lilly pillies from seed

For the last two years I have tried growing lilly pillies from seeds that I have collected. I placed them in a brown paper bag till they dried out and then planted them just bellow surface in a shallow tray filled with a good potting mix - but I allways have a low success rate of around 40%.

Can anyone please help?


   Syzygium wilsonii

Photo: John Wrigley
Click for a larger image

There are a quite a few plants that go under the general name of "lilly pilly". They are members of several genera including Syzygium and Acmena. As far as propagation is concerned they all have fairly similar requirements and you don't seem to be doing too much wrong.

The only thing that I can suggest is that you sow the fruits as soon as they are collected rather than waiting for them to dry out. Lilly pillies germinate best when fresh so storing them while they dry out may mean that some viability is lost.

However, 40% gemination success doesn't sound too bad - I wouldn't be too disappointed with that success rate.


Growing Pandanus

I'm hoping you can help me with information regarding Pandanus trees and also who can supply three or four large plants for my garden beds.

We live on the mid north coast of New South Wales and our house has just been completed. The garden beds have quality soil ready for planting. I've been warned off pandanus for three reasons:
  • apparently they have spiky trunks that are not kid friendly ( I dont seem to remember them being that bad);
  • apparently they may not appreciate my good soil - preferring more harsh/rocky conditions and may not appreciate regular watering (so should I avoid aiming watering system sprayers in their direction and let them fend for themselves once established?).
  • the tube like root system may outgrow the spaces I am expecting to use for the trees in my garden (the concrete edging is already laid, so the garden shape cannot change).

I really want the plants but am having a lot of trouble finding anyone that knows anything about them.

HELP, please !!

I'd really appreciate it.

New South Wales

Pandanus tectorius   
Beach front plantings of Pandanus tectorius


Unfortunately I can't advise on where you might obtain mature specimens. I suggest you get in touch with specialist native plant nurseries (probably Queensland nurseries would be most likely to be able to help).

There are a number of different species of Pandanus - some can get very large with massive tube-like roots that may well be too large for the position you mention. There are some other species which may be OK. I recall seeing Pandanus tectorius (I think it was that species) growing along the beachfront near Lennox Head. These were about 3 metres x 3 metres and the trunks didn't seem spiky. Another possibility is the screw palm (P.pedunculatus) but that species does have spines on the leaves. You'll have to ask around to see what species (if any) are available.

I doubt that soils and watering would be a problem. They are generally sub-tropical to tropical species and usually occur naturally in high rainfall areas.


Trees for wind resistance

I am hoping someone in your organisation can offer me some advice. I live just outside Hobart and have been trying to create a garden around our home. In parts I have been successful but part of the garden is exposed to the wind and I am finding it hard to find plants that can cope with these conditions. Some take and then months later the wind has killed them off. I have tried to build wind breaks, all to no avail. These land gales have more than tested my persistence. have you any suggestions.


I don't want to sound negative but this is a difficult question to answer adequately. I have access to lists of wind resistant trees but these are general lists and not categorised according to the various climatic zones of Australia. I have only a limited idea of your climate and soils and the problem is that plants that succeed in one area may be totally unsuited in your area. Added to this is the fact that the lists are based on plants that are wind resistant when mature, not when you're trying to establish a garden.

Listed below are some species that I think would suit your area but you would be best advised to talk to local nurseries (particularly specialist native nurseries) - they would be able to draw on local experience. You'll find some Tasmanian nurseries listed on our website.

Banksia integrifolia
Callistemon citrunus
Corymbia gummifera
Eucalyptus crebra

Eucalyptus lehmannii
Grevillea robusta
Podocarpus elatus
Syncarpia glomulifera
Tristaniopsis laurina
Westringia fruticosa


Toxicity of bush foods

I am interested in growing certain types of native "bush food" plants but someone just mentioned to me that I should grow these plants from cuttings of known chemical variety as the toxicology issues are a consideration.

Is this an issue I should be considering?

I would only be buying seeds of plants I have researched as being edible from credible nurseries. Could there be a problem like this?


This is a fairly specialised question. It's certainly not covered in any references that I have on potentially poisonous species.

Logically it stands to reason that propagating by cuttings from known non-toxic forms would be safest as seedling variations could result in the toxicity levels between seedlings varying. However, I'm not aware of any toxicity problems in growing known 'safe' bush foods and I don't know of any research that has been carried out on this.


Propagating Acacia attenuata

I have Acacia attenuata growing on my property and wish to propagate and care for the species.

Do you have any information on this species which might be of assistance?


There are no specific issues with this species. It responds to the usual treatment for Acacia seed - soak in boiling water, sow seeds that swell after soaking (re-treat those that don't swell) and sow in a coarse sand/peat mix (about 25% peat) or a normal seed raising mixture. Transplant into small pots when the first or second true leaves appear.

Further info can be found on our web site on the Propagation Pages and on the Acacia Page.


A sick grass tree

   Xanthorrhoea johnsonii
   A hillside of grasstrees
Photo: Alfred Guhl

I have the a Xanthorrhoea specimen in a pot and the outer leaves have started going a yellow colour. Is this due to a lack of water or perhaps the pot is too small?

Your assistance would be greatly appreciated.


All large grass trees are dug up from the wild and put into pots. Some take this treatment better than others and it could be that the plant is not finding the conditions in the pot ideal.

I doubt if lack of water is the problem - I'd expect that leaves would dessicate rather than turn yellow if water stress was the problem Too much water, however, is a possibility. Try cutting back the water - only water if the surface soil is dry to the touch.

If the plant has been in the same pot for some years, it might be worth potting into a larger container. If you do this, use a good quality potting mix designed for native plants. These sort of mixes usually have less nutrients than the more general mixes and, in the case of grass trees, that's probably an advantage. Try to keep the root ball intact when repotting.


What seed pod is that?

I have found a seed pod in Hyde Park, Sydney, and have been unable to identify the tree/plant that the pod originated from. I suspect that it may have been brought into the park as part of native mulch. I have attached photos of the pod and hope that you may be able to identify it for me.


   Flindersia australis

Click for a larger image

Fortunately this is one of those plants that has a distinctive pod. The plant is Flindersia australis (Crow's ash or Australian teak). I suspect that the original tree is growing somewhere in the Park as it's a species that is fairly often cultivated.

A quick search on the internet brought up some information and photos of the tree, flower and fruit on the BRAIN website (Brisbane Rainforest Action and Information Network).


Growing 'Great Morinda'

I came across your website while searching for Morinda citrifolia information.

I'm not sure if the hype about 'Noni juice' is true - can you tell me your opinion and if it is good, can I access some seeds to grow some in my backyard?


Just to clarify for readers who aren't aware of the hype.....

Morinda citrifolia is native to tropical areas of Queensland and the Northern Territory. It also occurs in Asia and Polynesia.

Morinda citrifolia   

Photo: Keith Townsend
Click for a larger image

The juice from the fruit is regarded as having a range of medicinal properties. In fact a small industry has buit up around the fruit which is being marketed as "Tahitian or Hawaiian Noni". The juice is high in vitamin C and there is a high demand for it as an alternative medicine for a host of illnesses.......arthritis, diabetes, high blood pressure, muscle aches and pains, menstrual diffiulties, headaches both mild and severe, heart disease, AIDS, cancers, gastric ulcers, sprains, mental depression, senility, poor digestion, atherosclerosis, blood vessel problems, drug addiction and more! Scientific evidence of the benefits of the juice is limited but there is some anecdotal evidence for successful treatment of colds and influenza.

The following sites provide some background to the commercial use of the juice.

The Society doesn't have any opinion on the effectiveness of 'Noni juice'.

Personally, I suspect there are probably some health benefits associated with the product and I don't dismiss all of the hype but I suspect that some of the claims are over enthusiasic.

I don't know of any specific source of seeds. I can only suggest that you try some of the seed suppliers listed on our web site, particularly those in tropical areas.

You may have trouble growing the plant in the Sydney area. It's a tropical species and it may be difficult to establish here. I don't know of anyone growing the plant in Sydney (but that doesn't mean there aren't any).


Propagating Christmas Bush

My neighbour has a couple of New South Wales' Christmas bush plants (Ceratopetalum gummiferum) and has kindly szaid that I can collect seed and/or cuttings.

I would like to try my hand at propagating this tree from both seed and cutting. Can anyone give me some advice about when it would be best to collect seed and how I should go about germinating it and ditto for cuttings - when, should they be tip, softwood or hardwood cuttings. I've heard that they are difficult to grow from cuttings. Is this so? How might I improve my chances of success?

Many thanks in anticipation.


There are no special "tricks" in propagating Ceratopetalum.

They can be grown from seed by sowing when the "flowers" start to drop early in the new year. The "flowers" are actually the calyx of the fruit containing the seed. Just sow the entire calyx in a seed raising mix and keep moist.

The only problem in growing from seed is that it's not possible to guarantee that the resulting plants will be as good as the parents. This is due to genetic diversity (of course, the resulting plants could equally be better than the parent - there's just no way to tell until the new plants start flowering).

Cuttings will produce a plant identical to the parent plant and this is the preferred way to propagate plants with desirable characteristics. Ceratopetalum can be a bit difficult but if you take quite a few cuttings you may get a few to strike. The best time would be late January when the new season's growth has hardened a bit but they may take several months to form roots. Again, there are no special tricks but use of a root-promoting hormone is recommended (available from garden centres).

There are general guidelines to seed and cuttings on the ASGAP web site.


Strangling vines on an acacia

Has anybody experienced a vine(creeper) which eventually swamps acacias to the extent you can barely see the foliage? What might it be? It is string-like with no leaves.

I have noticed it particulary on the Cootamundra and black wattles .


It sounds like "dodder", a group of native parasitic vines. They belong to the genus Cassytha. If it's a problem, physical removal is really the only solution.


Pruning grevilleas in California

I have been reading over the information on pruning grevilleas that you have on your site, plus as much as I could glean from the web, and I guess I have one little question.

   Greevillea hybrid

If it is recommend to prune grevilleas in Australia in October or so (after the major spring flush as one site notes), would that still hold true for me to prune one in our spring here (March or so) in Northern California?

Here's the problem- we have a 'Poorinda' hybrid here (I'm beginning to think it might be a 'Poorinda Constance') that is WAY out of control (about 3 metres high and at least or more wide). It really needs to be taken pretty far back but it is putting off new flowers right now and there are hummingbirds all over it - our local Audubon Chapter would kill me if I mess up this plant! By late spring we have three species of hummers fighting over it so I would hate to prune it back then. Actually, the only real quiet time is late fall (our October!). And then, when I do take it back, how far do you think it would be safe? I might do one 1/2 and not the other to leave some flowers...we do have some small specimens planted nearby but they really need another couple of years to catch up to this one.

Anyway, I hope that you can help me wrap my head around this time/season riddle! Thanks!


Interesting problem! And that's a very impressive grevillea!!

I don't think that the time of pruning is all that critical. The recommendation to cut back in late spring (rather than later in the season) is to avoid cutting off developing flowers and to avoid producing soft, new growth that could be damaged over winter. If frost isn't a problem, then pruning in October should be OK but your suggestion of only cutting back part of the plant is probably the safest option.

In my experience, the Poorindas shouldn't be cut back quite as hard as some others. Cuting back by about a third should be OK provided you aren't cutting into bare wood (ie. there should be some foliage remaining on the pruned stems.)

Hope this helps.


Geting rid of a Jacaranda

I live in a semi arid region of California. 2 year's ago I purchased a house with 5 Jacaranda trees on the property. The root's were getting into everything, so we had the tree's cut down, however they don't want to stay that way. In a 3 day period, any piece of the Jacaranda left in the ground will grow at least a foot in height, and now that they are invading the patio, is there anything on the market that will kill the roots of this particularly nasty tree?

We have tried everything from rock salt to pool chlorine, which is about 50 time's stronger than regular chlorine! I am at my wits end with these trees that keep popping up, do we literally have to dig up the entire root system?

One thing I've noticed about these trees is that you can literally plant a dead piece of the tree and if it gets water it will actually start to grow. We have burned the stumps, that doesn't stop them, we have pulled as much of the root as we can find, and that does not stop them, nothing seem's to stop these things!

How do you get rid of an unwanted Jack in Australia? I mean completely?


Difficult to know....

Although jacarandas are widely grown in Australia, they aren't Australian native plants and the Society doesn't have any special expertise to offer.

They are known to sucker here but I've never heard of any being as vigorous as the ones you have.

I would expect that glyphosate (Roundup) weed killer would eventually work but it will probably take persistence in treating every sucker as it appears. As glyphosate works best when plants are actively growing, it can sometimes take some days (even weeks in cold weather) before any effect is noticed. You might also have to follow up treating the same sucker after a couple of weeks.

Apart from that I don't know of any other way to eradicate the plants other than physical removal of the roots which is probably impractical.


Poisonous plants guide

I am enquiring whether you could send any information, pamphlets or direct me in the right place for information regarding poisonous plants.

I require advice on suitably safe plants that are accessible to children within their playground. We have a 1 metre high wall and soil behind it only half a metre wide with a very high fence behind that. So a small shrub or hedge would be suitable to break up the large area of fence. We also require safe and appropriate plants for hanging baskets and free-standing pots.

It would be greatly appreciated if you advise please!!!

New South Wales

The article "Australian Native Poisonous Plants" in the September 1997 issue of 'Australian Plants online' may help.

There are a few other internet resources that might also be worth checking out:

Apart from these, the staff at the National Botanic Gardens may be able to advise about the toxicity of specific plants.

Hope this helps.


Are kangaroo paws poisonous?

   Anigozanthos 'Regal Claw'

I was wondering if anyone can tell me if Kangaroo Paw (all plant parts) is known to be non-toxic to animals (cats/dogs in particular)?

I've been searching and have been unable to find it on any databases of poisonous plants (including the list of poisonous natives on your website), but I haven't found it on any non-toxic plant databases either. If anyone can shed any light on what is known that would be greatly appreciated.

Western Australia

I'm not aware of Kangaroo paws being toxic to humans or animals. They are certainly grazed by native wildlife and rabbits without any apparent ill effect. I've had cats and kangaroo paws for many years and haven't observed any problems.


[Front Page] [Features] [Departments] [Society Home] [Subscribe]

Australian Plants online - March 2004
Association of Societies for Growing Australian Plants