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Electronic Mailbox

The following have been selected from the questions received on the SGAP World Wide web site over the past few months and from contributions directed to the Electronic Mailbox specifically. You're welcome to comment on any issue concerning Australian native plants....growing, propagating or appreciating...anything.


Plants for Pots

Please suggest natives suitable for growing in small to medium size pots on a balcony.

Patrick Macalister,
Australia


If the balcony is in the open air, the range of plants is almost unlimited. Virtually any small to medium shrub would be suitable although you will have to be prepared to do some re-potting every few years and this may include some root pruning when it becomes impractical to re-pot into a larger container. Some suggestions for 300 - 450 mm diameter pots:

  • Small acacias
  • Small to medium banksias
  • Correa reflexa
  • Correa baeuerlenii
  • Epacris impressa
  • Epacris longiflora
  • Eriostemon myoporoides
  • Small bottlebrushes
  • Small melaleucas
  • Small leptospermums
  • Isopogon anethifolius and other isopogons
  • Phebalium squamulosum
Correa reflexa
Correa reflexa (27k)
Epacris impressa
Epacris impressa (39k)
 Select the thumbnail image for a higher resolution image
In larger tubs try:
  • Banksia serrata
  • Banksia integrifolia
  • Most rainforest plants
There are several books which might help. Two quite useful ones are "Growing Australian Natives in Pots" by Alec Blombery and "Growing Native Plants Indoors" by John Wrigley and Murray Fagg. I think these are out of print but they are available in many libraries.


Salinity - A Plea for Help

I am a keen Australian plant grower, particularly helping out with the local community nursery where we grow trees for farmers and others to help fight the battle of salinity.

The town itself (Katanning, Western Australia), is also suffering badly with many trees dying in the previous summer in one of the local parks, a survey revealing the water table only 400 mm below the surface and that it was about 3 times saltier than sea water. Talking to our local Landcare coordinator, our town apparently has the second highest consumption of water of any town in this neck of the woods and I suspect a fair quantity of this is going to keeping the grass green and gardens well watered during summer.

I would very much appreciate information on low water need gardens and plants suitable for our extreme conditions. Not everyone can be expected to embrace indigenous plants and many people do grow lovely WA specimens in their yards ( which I am noting !). Even mulching here is a bit of a novelty.

We are in the 600 ml rainfall belt, sandy grey soils, sometimes water repellent and in some cases residents have to deal with a water table only a spades depth down in their garden. I remember last time I was in Melbourne that the Botanic Gardens had a developed a section of xerophilic plants that had low water consumption. Is my memory right ?

I would dearly love any information on how to help people grow gardens that will survive these conditions and use less water that the current consumption figures suggest. I am hoping to start to develop with the Landcare coordinator some education material for residents on how to create a garden that will help fight the salinity and not feed our rising water table.

Any suggestions much appreciated.

Kim Zidarich,
Katanning, Western Australia
email: katz@henry.katel.net.au.


Could any readers who have experience in growing plants under the sort of conditions outlined or who have suggestions as to contacts, please contact Kim directly. There are several books which have lists of plants suitable for arid areas, including:

  • "Australian Native Plants", 4th Ed (1996) by John Wrigley and Murray Fagg (Reed Publishers)
  • "The Encyclopaedia of Australian Plants Vol.1 (1980) by Roger Elliot and David Jones (Lothian Publishing)

More Help Needed.....

"Grey Ironbark" (Eucalyptus paniculata) is one of the heaviest and strongest of all timbers. It has been used extensively for building bridges, wharves, wool stores and heavy structures in Aust. I am attempting to find out if any cultivars exist for this species, which have been selected for timber quality. "Ghittoe Wood" was used extensively during the last century also as a structural timber. Recent engineering tests have shown that it is probably the strongest of all the worlds known timber in a beam form, (Dry weight of 950kg/m3). This timber is very scarce and virtually unprocurable in the milled condition, and is classified by many wood turners as being a precious timber.

I am interested in any information regarding the present and former natural distributions of these two species. Are any seeds or seedlings of these species available, if so were these collected for any particular property (timber, flower etc) or are they simply representative of the species. Any data available for these species would be greatly appreciated.

M. Wallace
Australia
mklwmx@echidna.stu.cowan.edu.au


I don't have any information on the commercial applications or selected cultivars of either of these species. If anyone can assist Martin, could they contact him directly.

The Problem with Cats

I have to thank you for your wonderful site and e-zine. Its really terrific. As an information provider you really live up to the title - there's so much great info. on your site. I printed out the "Grey and Silver Plants" page....I love the idea of the silver lined drive way! And I'd been thinking of buying the 3D landscape program but now I think I'll take the plunge. Sounds like fun.

On the cat issue - I have a cat and I must confess she goes outside on weekends but there's nothing for her to kill where we live, probably because there are so many cats in the area! Well, I think people's ideas about cats can only be changed gradually. They need to be convinced that cats aren't a low maintenance pet that can look after itself. They need convincing that its not cruel to keep a cat indoors and its not natural for them to hunt native animals. In Sherbrooke (Victoria), where you'd think people would be most aware of what is at stake, they couldn't introduce permanent confinement so I think Council needed to start with a curfew and registration with permanent confinement to follow at a later date. I wouldn't have a problem with confinement right now but people have some stupid ideas about cats and animal protection groups will fight tooth and claw :-) for the rights of cats over wildlife. Amazing isn't it?


On the newsgroup rec.pets.cats I have often seen people from Nth America writing casually of the squirrels their cats bring home and their only concern is for the mess they have to clean up. When challenged on the issue they defend their cats as being part of nature. However, I think the impact of cats in Nth America is lessened by the fact that there are so many other wily predators in that continent. Some people suggest we should adopt Quolls as cat substitutes here but I've read that others predict that a quoll population similar to the domestic cat population, and with the artificial human support that cats enjoy now, could wreak more damage than cats do.

Well you asked my opinion and as you see this is a bit of a hobby horse for me. Sorry!

Thanks again for the SGAP site.

Samantha Lane
Australia


Thanks for the kind words about the SGAP site....we'll keep trying to keep the information flowing!

Mentioning the word "cat" to an audience when native animal lovers are likely to be in the majority always gets a reaction. My views are similar to yours but I doubt the general population is ready for total confinement of their moggies. The dawn to dusk curfew is a good start but I'm not aware of any other Council following Sherbrooke's lead.

I wonder if breeding has a role to play here. We have a "Spotted Mist" (an Australian breed) and she would gladly remain indoors at all times, given the chance. I wonder if this is a characteristic that can be enhanced by breeders.

Grasstrees

We have many grass trees (Xanthorrhoea species) and I would like to know about cultivating these.

Paula Shoulder
Australia


By chance there was a short article on these in the latest issue of the Society's journal "Australian Plants" (June 1997). I have included it below...I hope it helps. These plants are fairly commonly called "Blackboys", a term which is regarded by many as derogatory to aborigines and which is discouraged.



Grass Trees In The Bush and For The Garden

Judi Mullineux

A joy of bush walking is to meet along the way a noble Grass Tree. The genus, Xanthorrhoea, is related to the lilies. but is the only genus In a separate family, Xanthorrhoeaceae, found only in Australia. The grassy tuft rots away to form the trunk, sometimes 4 to 5 metres tall, a very slow process.

Grass Trees are fire tolerant. frost hardy to -70 degrees C, in normal rainfall conditions and endure drought, tolerating very poor soil. With their foliage they make a beautiful feature in any garden or rockery. They need a well drained, sunny position. Flowering is spasmodic, often brought on by fire. It is a joy to behold, the green stalk growing tall with many tiny creamy flowers on the spike. Native bees and birds enjoy the nectar. The dry flower spike can be used in dry flower arrangement.

Transplanting is reasonably easy. I do not suggest you go bush for these plants, but if you know of any that are threatened by road works, clearing or development obtain permission to remove and transplant the grass tree. Prepare a 2 m wide by 1 m deep hole, keeping the area moist before you bring in your grass tree. These trees do not have a tap root, the normal transplanting procedure, trimming old roots, removal of old vegetation from the crown, with generous watering for some weeks, should ensure a successful transplant. Nurseries carry mature plants for resale, but their origin is in doubt.

Propagation of seed is also possible as long as you are patient. Growth is slow but within three years, you should have splendid specimen for your rockery. The leaves will form a tussock, the trunk will take many years to form. There are reports of flowering after 10 years for Xanthorrhoea australis.

Grass Trees are spectacular in the wild often growing very tall. I have been overwhelmed by the HEIGHT of some X.preissii growing near Mandala Beach Western Australia in very open sandy country. Near Perth I came across a small forest of X.preissii, a stand of a couple of hundred trees growing alone in black sandy loam, very beautiful, very old specimens with blackened trunks from fires. In the Karri forest of south western Western Australia there are some very fine specimens of grass tree, their trunks branching once or twice, bending and twisting. Here in south eastern Queensland X.resinosa has a shorter trunk growing in Eucalyptus forest, in poor soils. Sealing wax and varnish is made from the resin of Xanthorrhoeaceae.


Deflasking Kangaroo Paws

Would anyone have any information on the method of deflasking tissue cultured kangaroo paws and the likely success rate?

Sandra
Australia


It's been a few years since I deflasked Kangaroo Paws but it's not particularly difficult.

  • Carefully tip the small plants out of the flask and separate them
  • Pot them into individual tubes in a mix of say, 25% peat moss and 75% coarse, washed sand
  • Put the tubes into a poly house under mist for a few weeks until good root development has occurred
  • Harden the small plants by gradually exposing them to open air conditions
I found that this method gave better than 90% success rate. If a poly house and mist is not available, a cold frame would do. The idea is to treat the small plants in a similar manner to cuttings until they are hardened.


Western Waratahs!

Telopea speciosissima All attempts to grow waratahs (Telopea speciosissima) here in Perth have failed. Is it at all possible to grow them in Perth's climate?

Jim Frossos
Perth, Western Australia


Select the thumbnail image for a larger resolution image [33k].

I referred this question to John Wrigley, a well known authority on the horticulture of Australian plants and he responded as follows:

"Waratahs require excellent drainage and they are prone to Phytophthora dieback. You should be able to grow them in Perth by giving them full sun and by building up the garden bed to about 1 metre above the surrounding area. Apply a good mulch of well rotted organic material and try and keep the soil evenly moist but not wet.

If this fails try them in a large container. If you are still unsuccessful, try to obtain the cultivar 'Shady Lady' which is definitely hardier but the flowers are smaller."

Carrotwood

I live in Central Florida. I was just recently given 2 saplings of a Carrotwood tree. I need to know as much as I can find out about them before I plant them. Just everything possible. Need to know whether it is a tree that I should be concerned about regarding its root system, and if it needs to be planted far away from sidewalks, driveways, pools and plumbing lines. I also need to know how well it withstands water. I haven't been able to find anyone around here, in the professional business of gardening, that knows anything about these trees, so I hope that you can provide me with any and all info I might need.

I would really appreciate your response to me asap, as I have the saplings in a temporary holding space at the moment. And are all Carrotwood trees from Australia? Think you can help me?

Name not supplied
Florida, USA


I think the plant you are referring to is Cupaniopsis anacardioides. We don't call it "Carrotwood" here; it's known as "Tuckeroo".

The plant is a rainforest tree to about 15 metres but often smaller in cultivation. I don't have any knowledge as to how big it would grow in your area. I also have no information about its root system but, as a reasonably sized tree, it would be best located away from underground pipes, paths and building foundations.

As for it "withstanding water"...it depends on what you mean. It is unlikely to be happy in waterlogged soils but, as a rainforest species, it will tolerate high rainfall.

The plant is regarded as very hardy in tropical to temperate climates and responds well to watering and applications of fertilizer. It can be slow growing. The only info that I can find about pests is that the seed can be destroyed by caterpillars, at least in Australia.

I should issue a word of caution here. The Florida Exotic Pest Plant Council regards this plant as a weed threat. It is apparently invading natural areas in parts of that state. You can learn a bit more about this in the article "Three (More) Rogue Aussies!" which appeared in the December 1996 issue and which can be obtained from the "Treasure Chest".

There are about 60 species in the genus Cupaniopsis and only 7 are native to Australia.

Small Tree Wanted

Could you recommend a small evergreen tree (maximum HEIGHT 15-20 ft) which would do well in Northern California (mild, frost-free climate with three months of light winter rainfall) and allow underplanting?

Tristaniopsis laurina I know Tristania laurina is available at nurseries here, but I can't get information on how dense the foliage gets as it matures, and whether the roots would compete with other plantings under and near the tree.


Select the thumbnail image for a higher resolution image. (38k)

Vara Ramakrishnan
California, USA


I would expect that Tristania laurina ("Water Gum") would be suitable. It's only a small tree and it doesn't have an excessively heavy crown of foliage. The yellow flowers are well displayed during summer. It's root system is also not particularly vigorous, however, any tree will have a reasonably extensive root system and will compete for water and nutrients with underplantings. This means that you will need to make sure that sufficient water and nutrients are available for all the plants.

I've successfully established a number of shrubs and ground covers in the root zone of this species (we call it Tristaniopsis laurina by the way - it underwent a name change a few years ago).

Melaleuca (Tea Tree) Oil

I am doing an Internet research project on the benefits of citrus- or natural oil-based cleaning products. I know that melaleuca oil is one of the best. Could you provide me with any information (especially web-sites) where I might find melaleuca oil info?

Christina Lance
Pennsylvania, USA


There is some on-line information provided by growers on the north coast of New South Wales. Tea Tree Traders provides some details on uses, technical specifications, Melaleuca plantations and products available.

There is also an article on the beneficial uses of the product in "Short Cuts" in this issue of "Australian Plants online".

Kangaroo (and Other) Grasses

I have acquired a new small yard. I have already determined to "go native" and I am currently observing the seasonal changes, amount of sun etc. before making big changes. The one thing I have decided, however, is that I wish to get rid of all the couch grass. I wanted something that requires almost no mowing. I was originally thinking of a herb lawn, thinking that nothing in the natives would suffice, but realise that I don't know enough about Australian natives to make such a judgement.

I read an article in a recent "The Australian Gardener" by Angus Stewart referring to Kangaroo Grass. Can you tell me about it? Does it require mowing, does it survive light foot traffic, does it need a lot of sun, etc.? If it is not suitable, could you suggest where I should start the search?

Thank you for the great site.

Cher Scott
Australia


Thank you for saying so........

This is a difficult one...there are few Australian native grasses that seem suited to traditional lawns but one or two are starting to appear.

Kangaroo Grass (Themeda triandra or Themeda australis, depending on which botanist you talk to) is a very common grass which is found in all states. Left to its own devices, the leaves reach about half a metre and it produces arching flower heads. It's a very attractive grass but won't take constant mowing and seems unsuitable for a maintained lawn. It does recover from the occasional cut back.

I recently read of an Australian turf grass called "Dryarna". Unfortunately I didn't record the details of the distributor but perhaps some reader may know something about it.

The only other contact I know of is a company in Windsor, New South Wales who claim to deal in native turf grasses. The company is ABULK Pty Ltd, phone 045 775912 or fax 045 775736.

Grevilleas in the UK

Just a quick note to pass on a reply from Shirley Clemo, Pine Lodge Gardens, St Austell, Cornwall to your request regarding which Grevilleas are hardy in Cornwall. Shirley has given me this list of species which she has shown to be hardy in her gardens.

(I hope that I get all the names correctly written down)

  • Grevillea alpina
  • Grevillea alpina "Olympic Flame"
  • Grevillea "Apricot Queen"
  • Grevillea "Canberra Gem"
  • Grevillea juniperina "Molonglo"
  • Grevillea juniperina prostata
  • Grevillea juniperina sulphurea
  • Grevillea lanigera
  • Grevillea rosmarinifolia
  • Grevillea rosmarinifolia "Desert Flame"
  • Grevillea rosmarinifolia "Jenkinsii"
  • Grevillea x semperflorens
  • Grevillea thyrsoides

  • Andy Ward
    Cornwall, UK


    Grevillea thyrsoidesThey look fine to me! The one major surprise is Grevillea thyrsoides (illustrated at left) which is native to a hot, dry climate. It's difficult to grow on the humid east coast of Australia, so success in Cornwall is definitely worth a "pat on the back".

    Select the thumbnail image for a higher resolution image. (41k)

    If other overseas readers wish to provide information regarding Australian plants they find to be hardy, too hardy (weeds) or not hardy, it would help us to build up a database of information which would be of great value. At the very least it would help us in responding to questions from overseas; at present it's difficult to respond to some of these because the enquirers often live in climates that we don't experience down under.

    By the way, the web page for the Pine Lodge Gardens is worth a look, particularly if you live in or are planning to visit Cornwall.

    Smoke and Germination

    Have you heard of the increase in seed germination with the application of smoked water? Why does this promote germination?

    If you could help it would be greatly appreciated!!

    Nicola
    Western Australia


    Well, I'm certainly no expert on this but it has to do with a theory that smoke from a bush fire may break down the inhibitors in certain seeds which prevent germination occurring. Smoked water is just a convenient way of applying the smoke to the seeds.

    By no means do all species respond to this treatment but some do.

    There was an article on this in the June 1996 issue of our magazine "Australian Plants online". That issue has now been removed from the server but you can download a copy via the "Treasure Chest" archive. There is also some information on the process at the Kings Park site.



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    Australian Plants online - September 1997
    The Society for Growing Australian Plants