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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!!


Unknown eucalypt in California

The accompanying photo is of a Eucalyptus species (could be an Angophora) found here in Fremont, California which to date, I've not been able to identify.

   Eucalyptus erythrocorys

The leaves are grey-green concolorous, opposite (or nearly so) and lanceolate, the bark is tan to gray, smooth and sheds in flakes, and the gumnuts are in threes, axillary, and on a 25mm long flattened peduncle. The gumnuts are exceptionally large 25mm wide by 30mm long, venous, somewhat bell shaped and have a red disk of an unusual shape (looks a bit like an enlarged red blood cell). The calyptra scar is uneven and appears to have 4 dried out regions that look a bit like teeth (this, and the opposite leaves led me to think of Angophora).

I saw it too late in the season to know the flower color. It hasn't hatched yet, so I don't have a clue on the seeds.

I'm out of my depth on this one and need your help.


I asked "Gumnuts" subscribers to help out on this one. Several readers responded and all agreed that the tree is almost certainly Eucalyptus erythrocorys, commonly called the "red cap gum". This is a very spectacular small tree suited to climates with a dry sumer (it's a marginal proposition in east coast areas of Australia - it grows reasonably well in Victoria but becomes more difficult further north. Obviously quite successful in California.

It grows easily from seed.


Grafting a "Silver Princess"

I am after information on possibly grafting a Eucalyptus caesia 'Silver Princess', or even if there are any grafted trees available for purchase.

Eucalyptus caesia 'Silver Princess'  
Eucalyptus caesia 'Silver Princess'
Click for larger image

I live in northern New South Wales and have tried several times to grow these beautiful trees with no success. I was wondering if a grafted one was available or maybe I could have a go at grafting one. I have never grafted a plant before but I was reading the Society Home page about grafting and thought maybe that might be the way to go.

Hope you can be of some assistance.

New South Wales

I'm not aware of anyone grafting Eucalyptus caesia 'Silver Princess' commercially although I agree it would be a good idea.

The problem in grafting eucalypts (or any plant, for that matter) is finding a compatible rootstock. There's been a fair bit of work done with the bloodwoods (these are the ones that you can now find fairly readily in native nurseries). Unfortunately, E.caesia is in a different group of the eucalypts so the rootstocks used for the bloodwoods are unlikely to be suitable.

E.caesia is in the sub-family Symphyomyrtus, so it would probably be necessary to use a hardy member of that sub-family as a rootstock. There are plently of possibilities as it's a big sub-family - some people may well be experimenting but I'm not aware of any work along these lines.

If you wanted to try grafting E.caesia yourself, you would most likely be doing pioneering work!


More propagation problems with "Silver Princess"

I've been attempting to propagate some Eucalyptus caesia 'Silver Princess' from seed and have struck some problems and was looking for some suggestions. I've lost 100% of a batch of about 70 seedlings first time around and now have lost about half the second batch; the rest I would like to save.

Here's the story. Everything goes well with the seedlings and I transplant to tubes, they continue to grow until the reach about 8-10cm in height, from there they literally fall over and die. When I inspect the remains, the root system is very shallow. The first batch I had growing in a soil/potting mix which actually got quite hard, so I figured that was the original cause. The second batch I've grown in a light potting mix and the same thing happened, small root system again.

At this size the stems/trunks are very delicate, more so than other eucalypts or the callistemons; (the mature tree also looks delicate with a narrow trunk compared to the height). My current assumption is that the foliage is too heavy to be supported and so it collapses. Do you think this is what is happening, is it something else, or are these just difficult to grow?

I've attempted to rescue the remaining 30-40 by extending the tubes with a plastic extension that will hold the plant up. Can I try something else? Snip off some foliage?


They can be difficult but you should be able to get a better success rate.

They can be subject to fungal diseases and it's best if they can be placed in a position where there is good air circulation and plenty of light. They can be put into full sun provided they aren't allowed to dry out.

It would be a good idea to stake them. I use small bar-b-cue skewers and tie them loosely with tie wire.

A good method to get deeper roots is to use capillary watering. See the notes on our Propagation Page.


Mystery plant - NSW north coast

Macrozamia fawcettii  
Macrozamia fawcettii
Photo: Allan Harris
Click for larger image

I wonder if it would be possible to identify a plant from the accompanying image?

The plant is growing in the hills behind Maclean, northern New South Wales and has the appearance to me of a prostrate Western Australian banksia. It would please me no end to know what it is,

New South Wales

It's undoubtedly a cycad - almost certainly Macrozamia fawcettii. According to David Jones' "Cycads of the World", this species occurs in the area where you found it. Macrozamias have separate male and female plants and the structures that you see in the photo are old male cones - a new male cone can be seen poking up below them.

It's apparently not uncommon but seems to be one of those plants that is not often seen because it's pretty inconspicuous when not fruiting.


Fire resistant plants

I was wondering if you could help me. I am looking for a listing of native plants that are resistant to fire for planting around houses etc in fire prone areas. Do you know where I could find that info? Thanks for your time.


This is a difficult question. There is a very tentative list on our web site.

However, there hasn't been much research into fire resistance of plants and the list is based on anecdotal evidence. ASGAP doesn't make any claims about the suitability of the plants. They are just plants that should burn less strongly than plants such as eucalypts that have considerable quantities of volatile oil in their leaves.


Non-flowering flame tree

Brachychiton acerifolius  
Brachychiton acerifolius
Photo: Alfred Guhl
Click for larger image

We have an Australian flame tree (Brachychiton acerifolius). We have had it for about 5 or 6 years, it is about 8 or 9 meters high and has never bloomed. Is there a species of this tree that does not bloom?

The tree was bought from a nursery and was advertised to bloom red in about 3 years.

Thank you for any information you can give.


All brachychitons flower but they can take many years if grown from seed - 10 years wouldn't be unusual for a flame tree seedling. A grafted plant would undoubtedly flower more quickly but these are rarely, if ever, available.

It would be very unusual for a seedling flame tree to bloom in 3 years.


Propagating a boab

Brachychiton acerifolius  
Adansonia gregorii
Photo: Aussie Outback Tours
Click for larger image

I collected some boab nuts (Adansonia gregorii) whilst in the Kimberley recently. Is it possible to propagate these in the Perth region, and if so how should I go about it?


I don't have any personal experience with this plant but my references indicate that germination is fairly easy if the seed is fresh. There are guidelines on germination procedures generally on our website.

I'm not sure that the plant will grown on successfully in Perth. It's regarded as being best suited to tropical areas.

Good luck with them.


Propagating mix recipes

I would like to try propagating, making up my own mix. Could you please advise me what to use and the ratio? I know there are propagating mixes on the market but I would like to have a go.

I plan to try cuttings first - eg. hydrangea, fuchsia, geraniums.


There are some suggestions for propagating mixes and propagation methods from cuttings on our Propagation Page.

The information on that page is aimed at propagating native plants but I would expect that the suggestions would be OK for the sort of plants that you have in mind.


Rust on blueberry ash?

My Elaeocarpus reticulatus (blueberry ash) has rust on some leaves. Can you pease advise what I should use to treat it?


Are you sure it's rust?

It's not unusual for older leaves to turn bronze/red with some brownish patches that might look like rust. This is normal and shouldn't be of concern.

Elaeocarpus reticulatus - leaf   

If you are convinced that it is rust, then you could treat with a fungicide - check with a larger garden centre for one effective against rust. However, I'd only treat as a last resort.


Lawn replacement

I have an area of lawn at the front of my house of about 5 metres by 10 metres. Given the water restrictions in Melbourne (and our need to conserve water in the long term), can you suggest Australian plants that I could use to replace the lawn? Native drought-resistant grasses, native ground covers? Perhaps it is too late to be planting this year? Am I allowed to hand water new plants? If it is too late to plant now, I can plan what to plant in autumn.


This isn't an easy question to answer with specific advice because it's difficult to know what plants are available from nurseries in the many different cities of Australia. There are many native plants that will do the job you want but their availability will vary from place to place because plants that do well in one climatic zone may not perform well elsewhere.

You might like to take a look at the article "Establishing Australian Plants - the Water Wise Way" in the March 2003 issue of "Australian Plants online". This article includes a basic list of plants suitable for many areas.

However, the best advice for your area will come from specialist native plant nurseries in your area - check out the list on our web site.

As a general guide, plants that originated in the drier forests and woodlands (as opposed to rainforests) have adapted to extended periods of drought and should be ideal for you situation. These sort of plants include many of the popular native species such as Grevillea, Callistemon (bottlebrush), wattles, Banksia, Hakea etc. I'd suggest a visit to a specialist native nursery to find out what they have available and to get local advice.

Regarding planting - I'm not sure of the water restrictions in place in Melbourne. Restrictions are in place in many areas of Australia at present but the way water is allowed to be used outdoors varires from place to place. You should check with your local authority to find out what restrictions apply to your area.

Autumn is undoubtedly the best time to plant as it gives the plants a chance to establish before the next summer. However, if you can hand water, you can plant at any time of year. During the first year or so, you will need to ensure that extra water is applied during very hot, dry periods. The plants may well be drought resistant but this only applies once they have established themselves and developed a strong root system.

I hope this helps.


Is this a Leptospermum?

Pileathus peduncularis  
Pileathus peduncularis
Photo: Don Manners
Click for larger image

The accompanying photo is of an unusual "Leptospermum" I saw recently in Western Australia. My interest was aroused when reading the article by Peter Ollerenshaw regarding his breeding program at his Bywong Nursery (see "Australian Plants online", December 2002). I have not seen any leptospermums with the tangerine colour shown in the picture.

I'm wondering if someone can identify it for me. If it is reasonably well know, why has it not been grown commercially.


Appearances can be deceiving!

The plant is not a Leptospermum - it's Pileathus peduncularis, commonly known as 'copper cups'. It's a member of the same plant family as Leptospermum but, despite the similarity in appearance, it's not especially closely related. It is more closely related to Geraldton Wax (Chamelaucium uncinatum).

This is one of those plants which has always been recognised as being worthy of wider cultivation but it has proved to be difficult to maintain in cultivation and is virtually impossible to grow in areas of summer humidity, such as coastal New South Wales and Queensland. Some reports have been received from time to time of success in parts of Victoria and Western Australia. I'm not aware of anyone being able to grow it successfully for a long period.


A gigantic Grevillea??!!

I have been given a Grevillea 'White Wings' but I can find no information about it. The label says it grows 3 metres high and 6 metres wide. I find this hard to believe.

Can you verify this for me and give me some more information about it?


Grevillea 'White Wings' is a very vigorous plant and could reach that size under ideal conditions. More typically is would probably get to 1.5 - 2 metres by about 3 - 3.5 metres.

It needs well drained soil and would be best in a sunny position. It doesn't perform well in very humid climates so it's not a plant for the tropics.


Growing Callistemon in Salt Lake City

I bought a small (1 gallon size) bottlebrush (Callistemon citrinus) and had it in a pot all summer long here in Salt Lake City (zone 6-7) I'm wondering if I should bring it indoors for the winter or try protecting it outdoors or planting it outdoors. It gets lots of sun and has grown well and flowered this summer. I would hate to lose it due to cold weather over the winter. Is any special care required if I bring it in?

Also, from your experience what are the hardiest of the bottlebrushes? Do you know of a supplier in the US?

Utah, USA

Bottlebrushes are not regarded as indoor plants in Australia and, like most plants native to drier forests and woodlands, they don't survive well indoors for extended periods. Whether the same situation would occur in your area, I can't say.

Callistemon citrinus  
Callistemon citrinus
Click for larger image

If it's possible to protect it outdoors, I think that would be preferable. I suppose it depends on how cold it gets outdoors. This species is reasonably frost tolerent here but we rarely get temperatures below -5 to -7 deg C.

Regarding hardiness generally - The hardiest bottlebrush depends largely on the local conditions. It's difficult to generalise but Callistemon citinus has proven itself over a wide range of climates. You might like to check out or Callistemon Page for some other suggestions.

There are some suppliers in the USA but I don't know of any in your particular area. Take a look at the list on our web site. Maybe you can find one that does mail orders.


A non-messy gum tree?

I would like to have a gum tree in our garden, but don't like raking leaves. Can you please advise if there is a gum tree that looses little or no leaves. We live in Western Australia where the soil is well drained and the height of the tree is not a problem.

Western Australia

I doubt if you will find any eucalypt that doesn't drop leaves and I'm not aware of any studies into this. All gum trees lose leaves, usually in response to water stress - it's a method of coping with lack of water. The amount of leaf drop would vary from season to season.

If you want a gum tree you really have to learn to love fallen leaves!!


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Australian Plants online - December 2003
Association of Societies for Growing Australian Plants