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Short items of interest about Australian plants selected from the many newsletters and journals published by member Societies of ASGAP.......
Short Cuts in this issue:
- The Queensland Tree Waratah
- One of Australia's most spectacular species
- Grevillea 'Poorinda Royal Mantle'
- Growing this common cultivar to perfection!
- Growing Ferns from Spore
- Expert advice on propagating your own collection of ferns
- The Genus Dianella
- Ideal for small spaces, this member of the Lily family should be better known
- Striking Cuttings in Water
- A simple propagation technique suitable for herbaceous species
- Favourite Vines
- A small selection for warm climates
The Queensland Tree Waratah
This magnificant species is arguably Australia's most spectacular flowering tree for tropical and temperate areas. Merv Hodge explains why it should be more widely planted....
In my lifetime I have grown the Queensland tree waratah, Alloxylon flammeum, twice from seed to flowering. This may not seem to be a big deal except that each time has taken about ten years.
The first tree was planted in our suburban garden on very heavy red clay. The tree grew well, but during the second flowering it was plucked out of the ground by a tornado that cut a swathe about 200 metres wide through Brisbane in November 1973.
||The large flower clusters are well displayed
Photos: Keith Townsend, Brian Walters
Click for larger image
My second try was on our present 2-hectare property in very different conditions. To ensure a better chance I planted three of them. There is no town water available and we have much drier conditions than I considered that this species could survive in, but it was worth a try.
The plants are amongst large sandstone boulders in decomposed sandstone soil. Other than mulching and initially watering by bucket, all three plants have survived without help for more than 10 years. They look quite healthy, but at about 4 metres high they are somewhat smaller than they would be in better conditions. I feel that it is incredible that they are doing so well considering our present dry conditions.
I was inspired to write this article because all three are now producing orange/red flowers, two plants for the second occasion. They have been quite spectacular for more than a month. This third plant is flowering for the first time and is only carrying a few spikes. The two larger trees carried seed from last years flowering and these were released
These trees were threatened by a fire that burnt out our eastern slope two years ago. I tried to save the one in most danger by vigorously raking mulch away from it. It became too hot and I bid a hasty retreat just as the Rural Fire Brigade turned up. I called out "Save that tree", and they did. I can only imagine what thoughts ran through their minds about my priorities. However, the house was not in immediate danger.
Sadly, we lost most of the other rainforest trees in the path of the fire. To be fair, many were old and rather poor plants that had existed for many years.
In the time that I have known this plant it has had a couple of name changes. It was originally known as Embothrium wickhamii, then Oreocallis wickhamii and now Alloxylon flammeum. The species name 'wickhamii' was incorrect and should have been applied to one of the other two species in this genus.
It can be propagated by seed, cutting or grafting. Seed should be sown when fresh, taking precautions against fungal diseases. The main disadvantage is the long time before plants flower. Cutting grown plants on the other hand can flower within a couple of years and will flower in pots. These have the disadvantage of a possible weak root systems and so are best planted in a sheltered position.
They tend to have lower and bushier growth habit than seedlings.
I occasionally graft plants by taking scions from mature trees and attach them to seedlings of the same species. The resulting plants have the advantage of a strong root system and early flowering. I am not sure how this will ultimately affect the height of the plant.
Mature plants have simple obovate leaves but immature plants have lobed leaves. Flowering first occurs soon after the appearance of the mature leaves. This also happens with other rainforest members of the Proteaceae family.
Established plants available in nurseries can be identified as seedlings or cutting grown plants by inspecting the leaves. Small seedlings produce mature type leaves first, then the lobed leaves.
The species occurs naturally in deep, red loams in remnant patches of rainforest on the Atherton Tableland. It is listed as a vulnerable plant.
I regard this as the most spectacular of our rainforest trees, but it is rather large for suburban gardens. Cutting grown plants could be more suitable.
Nectar feeding birds are attracted to the flowers.
From SGAP Queensland's "Bulletin", December 2002.
Editor's note: I have been growing Alloxylon flammeum for about 12 years in western Sydney - the plant has flowered well for the last 7 or 8 years. Like Merv, I have been surprised at the tolerence of the species for dry conditions. Mine was a cutting-grown plant and it has reached about 4 metres - certainly not too large for a normal garden, but the dry location may be a contributor.
For further information on this species, see the ASGAP website.
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Grevillea 'Poorinda Royal Mantle'
This popular cultivar has been in general cultivation and may tend to be overlooked in favour of more recent hybrids. John Wrigley suggests that you take another look at this vigorous groundcover
A number of Grevillea hybrids bear the name 'Poorinda'. It was the name of the property owned by the late Leo Hodge, a keen grower of grevilleas interested in hybridising the genus in the early 1950s. More than 50 Poorinda cultivars are registered but few of them are still available commercially, being superseded by superior selections.
Grevillea 'Poorinda Royal Mantle', often known simply as 'Royal Mantle' is, however, still with us and remains undoubtedly the best of the Poorinda hybrids. It is believed to be a hybrid between G.laurifolia, a species from the Blue Mountains, and G.willisii, an eastern Victorian species. Unfortunately Hodge's record keeping left much to be desired and the parentage of many of his hybrids is
|Grevillea 'Poorinda Royal Mantle' is a dense and vigorous groundcover
This cultivar is a vigorous groundcover, which will cover an area 3m by 3m if conditions are to its liking. There is rarely a time when there are not some flowers present but its peak flowering time is late winter and spring. The flowers are deep red in a one-sided toothbrush-like raceme about 6cm long. They are very attractive to nectar seeking birds. Leaves are variable, up to 10cm long with some being coarsely toothed and others entire. The young growth is coppery red.
For best results, a well-drained sunny position is preferred but the cultivar is tolerant of almost any position that is not waterlogged and in full shade. It is frost hardy, accepting temperatures to at least -7oC and in contrast has been seen growing well in Cairns.
Propagation must be from cuttings to ensure that the clonal properties of the hybrid are retained. Cuttings are best taken in December or January when the new growth has begun to harden. However, suitable cuttings may be found at most times of the year. The use of a hormone growth promoter, such as Clonex is beneficial.
From Native Plants for New South Wales, newsletter of the Australian Plants Society (NSW), October 2000.
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Growing Ferns from Spore
While many people are prepared to propagate a few plants from seeds or cuttings, few seem prepared to attempt growing ferns from spore. Barry White explains how it is done....
Preparing a suitable propagating medium
Any fairly coarse, porous material seems to be suitable. Very old, well decomposed, shredded soft tree fern fibre gives excellent results if available. Peat moss (unsieved) and crushed terracotta have been used successfully. Another alternative is a mixture of equal parts coarse sand and treefern fibre or peatmoss.
Pots 5 or 6 cm square are quite sufficient to grow a large number of ferns, enabling a few different species to be raised in a relatively small space. The pots may be filled with the chosen medium or a 2-3 cm layer may be added on top of your normal potting mix. The mixture may be sterilised by carefully pouring hot water through the mix and then standing the pots in hot water, up to the rim, in a closed container for an hour. The pots should then be removed and hot water poured through the mix for a second time and then allowed to cool, again in the closed container. An alternative is to microwave the mixture, which should be well moistened, for a period long nough to thoroughly steam the mixture. Sterilisation is necessary to kill off any moss or fungus spore, or unwanted fern spore, which might be present in the mix.
Sowing the spore
To sow, hold an open envelope containing the spore about 6-7 cm above the pot and give it a gentle tap to aIlow the spore to float down onto the top of the mixture. This must be done in a perfectly still room, completely free from any draughts or breezes. If the spore are sown too heavily the resultant prothalli may have to he pricked out early to avoid overcrowding problems.
Conditions for germination
Spore may be sown a any time of the year, but germination will be faster in the warmer months. For successful germination, spore must be kept moist at all times. This is simply achieved by placing the sown pots in a closed container (eg. plastic ice-cream container, food crisper, glass aquarium covered with a sheet of glass), or the pot may be just placed in a plastic bag. Provided the container is reasonably well sealed the pot should remain moist almost indefinitely. If it becomes necessary to add water, stand the pot in cool boiled water - watering from above may wash spores away. The pot should be placed in a well lit position but not in direct sunlight e.g. on a south facing window ledge.
In a warm, well lit position germination usually occurs in about 1 to 2 months and appears as very small green specks which gradually grow into flat heart structures (prothalli) about 1/2 to 1 cm in diameter. The initial growth may be mistaken for moss. Germination may take several months if conditions are not good. The prothalli, which are the intermediate stage of the life cycle of the fern, each have a male and a feina]e portion - the male portion releases sperm which swim across to feitilise the egg. The fertilised egg then grows to form the ferm proper. The first appearance of fronds may vary from 2-3 months (in very rapid species) to years.
Most problems result from overcrowding of the prothalli (from too heavy sowing) or from contamination due to poor hygiene. Fungi, mosses and algae may overgrow or damage the prothalli. Overcrowded prothal]i may be pricked out into another container as soon as the problem is noticed.
Mosses and algae are best avoided by carefiil hygiene - proper sterilisation of the mix and only using water which has been boiled. An open loose mix helps to avoid algal growth.
Pricking out and potting on
The thickness of the growth of the prothalli will often determine when to prick out. If the surface of the mix is heavily covered with prothalli, pricking out should be done at this stage by pricking out small clumps of prothalli into a mix prepared and sterilised as for the original sowing.
Usually, pricking out is done when the sporeling has one or two fronds although it may be done at any stage. The young ferns may be transplanted into standard propagating mix, or into a mixture of about 2 parts peat moss, 2 parts washed river sand and 1 part mountain soil. Before pricking out, the sporelings should be gradually hardened off over about a fortnight and subsequent to the pricking out be returned to cover under glass or plastic until safely re-established,
It should be possible to lift the sporeling off the pot with its prothallus still attached. At this stage the roots will usually not be well developed and the prothallus can be gently pushed down onto the surface of the new pot or tray to support the tiny plant. This should be done fairly quickly and should then very gently watered and placed under glass again. Treatment with a product such Maxicrop or Plant Starter will assist establishment of the new plant.
If the sporelings are allowed to grow too large and crowded before they are pricked out they may be scooped out in clumps with a spoon, placed in a saucer of water, and then gently separated and planted into tubes or trays. Again they should be replaced under glass without delay.
The newly transplanted sporelings should be allowed to develop under glass until their fronds are about 5 - 10 cm high. At this stage they may be very gradually acclimatised by slowly raising the glass cover, a few millimetres at a time, over a period of about two weeks.
Using the techniques outlined above, it is not unusual to grow one or two hundred ferns from each 5-6 cm pot sown with spore.
From the newsletter of ASGAP's Fern Study Group, September 2000.
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The Genus Dianella
Dianella is a genus of grass-like plants in the lily family. They are commonly encountered in bushland in eastern Australia but are less often found in gardens. Thais Eisen shows why you should take a closer look.........
Following good spring rain our local dianellas have been rapidly sending up their inflorescences of blue flowers with prominent yellow anthers.
Dianellas are monocotyledons and belong to the family Liliaceae. This family includes a range of native genera - eg. fringe lilies (Thysanotus), rush lilies (Sowerbaea) and Christmas bells (Blandfordia) as well as overseas genera such as Aloe, Asparagus, Allium (onions and garlic) and Lilium.
|Dianella species produce sprays of colourful berries after flowering
In common with most other monocotyledons, the leaves have parallel venation and the flower parts are in threes. The stems of our local plants are all short. The plants form clumps and are grass-like in appearance with one main vein in the leaves. The flowers are bisexual and can vary in colour from the usual blue to almost white. There are three petals and three sepals that look like the petals (petaloid) (ie. they are the colour and texture of the petals). There are six stamens with swellings on the filaments. The ovary is superior (ie. above the insertion of the other floral parts). The fruit is a purple/blue berry containing a small number of shiny, black seeds.
Dianellas are very common on local forest soils and there are four species at our place at Booie (near Kingaroy, Queensland), all of which flower in spring.
D.brevipedunculata is easily identified by the short flower peduncles. The inflorescence is hidden within the foliage making it difficult to see the deep blue flowers. This species forms large tufted clumps over 60 cm high and the same across. It is very common on sandy forest soils but does not seem to cope with drought as well as one would expect.
D.Iongifolia is similar in appearance to D.brevipedunculata as far as the leaves are concerned, but I have never seen a large clump locally. Most plants seem to have only one or two tufts of upright leaves. The most obvious difference is the long flower peduncle, which holds the flowers well above the foliage and may be over a metre high. Again the flowers are bright blue.
D.rara is difficult to see when it is not in flower as the leaves are narrow, mostly about 30cm long and few in number. They are a bluish green colour and often seem to be rolled lengthwise. The flower spike, however, is prominent and draws attention to the plant. The flowers are pale, whitish blue and strongly scented. This species is said to be rare but seems to be fairly common locally and may be thought to be rare because it is so difficult to see when not in flower.
The local form of D.revoluta has stiff upright, blue green leaves. It forms loose clumps up to a metre across which are not tufted but form a mat with each group of leaves at the end of a short rhizome. The deep blue flowers are held partially in and partially above the foliage.
If dianellas occur in your district and it is possible to leave part of your property unmown, these plants are a delight in spring.
From the newsletter of the Society for Growing Australian Plants (Kingaroy and District Branch), December 2001.
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Striking Cuttings in Water
Sometimes plant propagation is just too easy! Ross Doig describes a method that should produce success no matter how many times you've failed in the past!
In 1993 I began experiments with soft-stemmed cuttings in water and with seemingly little effort achieved enough success to warrant encouraging others, not only to propagate the plants mentioned below, but also to extend the range of species suited to this simple method.
In brief, glass jars, ex the kitchen, from small Vegemite to 500-millilitre size were filled with tap water to a depth of 50 millimetres. Cuttings between 250 and 300 millimetres were stripped of leaves on that part of the stem to be immersed, and from the part not immersed, only a few removed (if large).
The water was changed depending upon growth of algae. No hormones were used either by addition to the water or as a foliar spray. The cuttings were housed in various situations: a foam plastic box topped with clear plastic in a sheltered outdoor area, on a kitchen window sill and some covered with a PET bottle with the bottom cut out in a dry propagation house on a bench.
Times taken to form roots varied from three to twelve weeks depending on the time of the year and the condition of the wood or herbaceous stems. Roots formed were generally soft and grew rapidly. With some, aerial roots formed on nodes not immersed in the water.
When potting on. take care, as the roots tend to be soft and brittle. Most success came from herbaceous, soft stemmed plants and those listed here fit that category except for Kennedia prostrata, which was an unexpected success.
Scaevola 'Purple Pride', S.albida, S.aemula, S.ramossisima, S.'Purple Fanfare', Goodenia ovata prostrate form, G.ovata, G.heterophylla
Eremophila debilis, Myoporum parvifolium
Helichrysum scorpioides, H.rutidolepsis, Chrysocephalum apiculatum, Xerochrysum bracteatum (various forms), Senecio linearifolius, Rhodanthe anthemoides, R.floribunda, Brachyscome multifida, B.angustifolium, Calotis cuneifolia
Derwentia derwentiana - the success of this species suggests other desirable members of this genus would be equally amenable.
Hemiandra pungens from Western Australia struck readily indicating that other species and genera from this family would be worth trialing.
From "Eucryphia", newsletter of the Australian Plants Society (Tasmania), March 1998
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Peter Radke talks about a few climbing plants worth considering for tropical and sub-tropical areas (or even in a warm position in temperate areas.
I must admit that vines are not really my favourite type of plants (preferring trees and shrubs), so the title "Favourite Vines" needs to be taken with caution. However, I do think that some vines are very special and deserve a place in a good native garden. So, here's my selection.
Aristolochia tagala:Every garden in north Queensland should have several of these vines because they are the food plant of the spectacular Cairns Birdwing Butterfly. Don't be afraid that the vine will smother all your other precious trees, because it won't - the butterfly caterpillars will see to that. Always plant several vines. If you only plant one, there will not be enough food for all the caterpillars and they will starve.
Agapetes meiniana: This is my type of vine - it makes a really beautiful pot plant or hanging basket, and in this situation will never get out of control. It has beautiful glossy leaves and flowers profusely in a pot. I love this plant because every time I walk past it I am reminded of my favourite places, Mt Lewis and Windsor Tableland.
Pandorea pandorana: This is a very vigorous vine which flowers profusely. I've seen specimens out in the dry country that completely cover a gum tree and are solid flowers from top to bottom - absolutely spectacular. Perhaps a bit too vigorous for a home garden, but wonderful to see in the wild.
Tecomanthe sp. Roaring Meg: This is the northern version of the Fraser Island Creeper, Tecomanthe hillii, and is truly spectacular in flower, having huge pink bell-shaped flowers that hang down in clusters from the stems. Planted over a pergola, it is absolutely stunning, and truly the best ornamental vine for tropical Australia.
From the newsletter of the Tablelands Branch of the Society for Growing Australian Plants, May 2000.
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Australian Plants online - March 2003
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