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Short Cuts

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:

How to Grow Flannel Flower Easily

Tips for germinating seeds of Actinotus helianthi

Potting Mixes: Roots Need Room to Breathe

How to check it plants roots are receiving sufficient aeration

A Reliable Wax Flower

Why the long-leaf wax flower deserves a place in your garden.

Australian Native Grasses and Gardens

Why you should include grasses in your landscape

The Genus Boronia

All about this popular genus of Australian plants

The Late Inclusion of Trees in Garden Design

Factors to consider when planting trees in an established garden

How to Grow Flannel Flower Easily

Since my seachange from Boronia to Ocean Grove I have been able to grow a flannel flower (Actinotus helianthi)in my garden - IN THE GROUND - for the first time!

So by last January I had a large handful of plump-looking seeds to put to good use. I consulted a few books on how to grow them and decided to try the methods suggested with different, small batches of seed.

The methods tried were:

• Place seeds between pieces of fly-screen wire mesh and pass through a flame to bum off some of the dense hair covering the seeds.
  
  
• Rub or scrape off some of the seed hairs before sowing.
  
  
• Peel off the hairy outer skin of the seeds before sowing (this was my idea and it was very painstaking and fiddly).
  
  
• Because it also occurred to me that the purpose of these measures was to get moisture to penetrate through all that hairiness, I soaked the seeds in "Wettasoil". I used 3 drops of an ordinary "Wettasoil" from Bunnings* to one cup of tepid water and soaked the seeds for 1 hour. I then sowed the seeds in a seed raising mix using little punnets.

	Seeds of flannel flower

Results

• Method 1 - 1 seedling after 3 months.
  
  
• Method 2 - Nothing.
  
  
• Method 3 - Of 13 seeds, 8 germinated after 6-8 weeks.
  
  
• Method 4 - Eureka! 30-50 seedlings, the first to emerge after 4 and a half weeks, the last after 6 weeks.

Then I learned from the Australian Daisy Study Group** that I should have sown the seeds into individual small pots as they don't transplant readily. Panic! Immediately, I put the babies, still at the cotyledon stage, into 75 mm pots. Some were too close together to separate, so I ended up with 25 pots and lost, initially, only 2 in the transplant. To prove to myself that this result was no fluke I tried again. In the meantime, I had heard from Judy Barker (leader of the Daisy Study Group) that good results from Actinotus helianthi seed had been achieved by the 'smoke' method. As she had kindly given me some smoke-impregnated Vermiculite granules I ran two new trials.

Starting on 18.2.03, I used I litre icecream containers, weighed out equal amounts of seed raising mix and seeds and placed the containers outdoors, uncovered but under shade cloth and watered daily.

Results

Conclusion

The first method is slightly better than the second (which could be due to seed viability.) But it is cheaper for the amateur grower.

My trials continue. I have proved that seeds must be sown during the hot part of the year; seeds I sowed in April gave no results, in either my cold frame or on my son's heat mat.

* A milder, more plant-friendly soil wetter might be better.
** Yes - the Daisy Study Group and I know that Actinotus helianthi is no daisy, but a carrot!

From "Growing Australian", Newsletter of the Australian Plants Society (Victoria), September 2003.

Potting Mixes: Roots Need Room to Breathe

In order to grow, plant roots must respire, that is take in oxygen etc as do animals. Aquatic plants achieve this by various means such as hollow stems, pneumatophores (eg. mangrove roots that stand-up from the mud flats). However, most plant roots need to get their air from the medium in which they are growing. The nature of the medium, the physical situation, along with the frequency of watering determines the amount of air available to the roots.

To determine the air available to your plants try the following exercise.

Choose a container with a lid in which holes can be made. Mark an easily calculated level (eg 250 ml). Fill the container to the mark with the soil or mix, then add water to the same mark. Put 3 to 4 holes in the lid of the container about 1cm in size. Upend the container over a basin and measure the amount of water which drains out. This will tell you approximately how much air would be in the medium after watering. The standard for potting mixes is about 20% air. The table below gives an indication of the air content and soil suitability.

From the newsletter of the St George Group of the Australian Plants Society.

A Reliable Wax Flower

The long-leaf wax flower is so firmly entrenched in the general nursery trade that most people who grow it probably don't even realise that it's a native. But being common is no reason to ignore an excellent plant!

Philotheca myoporoides Click for larger image

It's probably better known under its previous name, Eriostemon myoporoides, and will still be seen labelled as such in nurseries.

The species is quite variable and some forms can reach 5 metres in height. The form commonly available, however, is a medium shrub to about 2 metres, dense in habit with dark green glossy leaves and white flowers in profusion in late winter and spring. It has proved to be very hardy in a variety of soils, but won't tolerate boggy conditions. Like many in the Rutaceae (eg Boronia, Correa, Leonema, Phebalium), it seems to prefer semi-shaded positions to full sun.

Propagation of the common form is easy from cuttings, generally taken from January to April. Some of the other forms may to slow to produce roots.

P.myoporoides is one of those reliable species which form the "backbone" of every garden.

Australian Native Grasses and Gardens

Many of us have marvelled at the ability of one of our tiny native birds to rest on the very, very highest tip of a shrub but have we reflected on how important it is to provide food for them in the garden? Many of them are seed eaters and particularly in urban areas grasses can be banished in favour of the more noticeable plants.

Australian native grasses were little understood and underestimated in the past and replaced by introduced 'improved pastures'. As we face the realities of the often harsh and fickle Australian climate they are being recognised for their steady production of fodder, ability to grow in less fertile soils and frost and drought resistance. They are coming into their own in revegetation. Roadsides have become a great place to observe these grasses.

Cymbopogon obtectus, Silky heads (left) and Notodanthonia longifolia, Long-leaved wallaby grass (right). Photos: (Kym Sparshott)

Every native garden should have some grasses to provide food for the seed-eater birds and small marsupials and for their aesthetic value, adding a different texture and colour whether it is the rich brown-red of mature kangaroo grass (Themedia triandra) or the dense tufts of fine blue-grey of Poa labillardierii, Cymbopogon refractus (barbed wire grass) as its name might say adds a strong accent while Danthonia, with seed heads covered in silky hairs, gives a softer touch.

You can start small with just a few clumps in a corner of the garden and expand by harvesting seed and propagating plants. It is a slow but rewarding business. Most domesticated grasses such as cereals are bred to retain seed in the head for a single harvesting. Australian native grasses are far better adapted for a natural process of seed dispersal by wind, water and animals. Seed is produced progressively along the seed heads. These seed heads are produced irregularly on the plant throughout the growing season. As seed ripens it falls to the ground , widening the period of possible germination but it poses a problem of time of harvest. Some grasses have one flowering period, some flower more than once a year, often in response to rain. All plants of kangaroo grass may not flower at the same time.

In the garden it is a matter of watching the seed heads as they ripen, running your hand up over the seed heads from time to time until seed comes away in your hand. Cut the whole seed heads off, put them in a paper (preferably brown) bag and put the bag in a warm spot for a week or two and there is the seed.

A slope covered in kangaroo grass makes a great back drop and the tufts of strap like leaves of the Lomandra are good front row specimens if you are not too tired of seeing them lining roadways in the millions. They are long lived and reliable as a landscaping plant. Their flowers exude a quite strong lacquer-like perfume and apparently the quite large seeds have the taste of fresh green peas. Poa can soften the edges along natural material steps and paths and under trees provided there is a good deal of light. Poa is happy around ponds and water ways.

Poa labillarderii seeds prolifically and planted in sharp sand with a touch of coco peat germinates well, and survives conditions of neglect. Each little plant of the grass can be potted on and will grow into a good healthy tuft for planting in the edges of garden beds. Try planting around the edge of a bed in the way people plant the introduced mondo grass. Run the lawnmower over it at the end of the flowering season and its blue colour will refresh in the autumn/winter months.

From the July 2003 issue of the Newsletter of the Central West Group of the Australian Plants Society.

The Genus Boronia

What a mixed up situation we have with this poor little plant family. Here we have an Australian plant part of a family which includes citrus trees from all over the world. This family has its name derived from a European herb, and the genus was called after an Italian who died in Athens. Boronia is also a plant that most people admire but few grow.

Boronia mollis (left) Boronia safrolifera (right) Click for larger image

Boronias are generally found in heathlands or dry sclerophyll forest where there is shade and leaf mulch to maintain the soil at a constant temperature. Their form varies greatly, most are shrubs of one metre or less. There are also prostrate forms such as Boronia polygalifolia from New South Wales and B.nana from Victoria and South Australia. This plant may only reach fifteen centimetres in height. There are also some very large species like B.thujona which can grow to four metres tall and B.mulleri which in good conditions may grow into a small tree of six metres.

All species are confined to Australia. There are about ninety-four species - twenty-two in Queensland, twenty-eight in New South Wales, thirteen in Victoria, five in South Australia, forty-eight in Western Australia, seven in the Northern Territory and seven in Tasmania.

The family name Rutaceae is derived from the herb rue (Ruta graveolens) which at the time was grown extensively in European gardens for its aromatic and medicinal qualities. The genus was called after Francesco Borone, an Italian helper of English botanist John Sidthorp. Borone was killed in 1794 aged twenty five in an accidental fall from a window in Athens. It was J. E. Smith who named the genus Boronia in 1798.

Many of the boronias have perfumed foliage as well as flowers. In the early days, attempts were made to extract its oil for commercial use, but this proved to be very difficult until 1924 when a process using volatile solvents proved successful. The oil was then extracted from brown boronia B.megastigma) until the mid 1950s, when it then became more economical for the grower to sell the flowers as fresh flowers.

Normally these plants are not easy to grow in cultivation. But selected species can be grown in containers using an open free draining mix. Care will need to be taken so they do not dry out. You will need to move them on a seasonal basis so they don't get too much sun. They will of course still be a little short lived, as they are in the wild. But they can be grown: so try. You never know your luck.

From "Gumleaves", newsletter of the Hunter Valley Group of the Australian Plants Society, June 2003.

The Late Inclusion of Trees in Garden Design

In the last couple of years I have planted many more eucalypts and allocasuarinas - approximately 40 in all. The garden, now almost structurally complete, was developed in stages over the last 11-12 years with the last major work being completed around 5 - 6 years ago.

Normally selecting and positioning trees would occur when working out what plants are needed in any newly developed seclion of the garden. A few trees were planted in the first stage of the garden's development and at each subsequent stage or development a few more were added but not nearly as many as I now think are necessary. So why did I delay in planting so many of the key structural elements in the plant design of the garden?

I had a number of concerns about possibly blocking a big view, creating too much shade or even worse still creating too much dry shade. Also I didn't know a lot about eucalypts, their reliability and growth habits. While I was busy learning the names and characteristics of many of my other plants, to some extent I put learning about eucalypts on hold. It was all just too difficult. So caution ruled the day - let's face it, if you make a mistake with your choice of tree then it may be a big mistake and a big problem before too long. This delay, however, gave me the chance to become familiar with the trees I have and work out what I want to achieve with trees in the total design.

As the garden matures I have been able to see how the inclusion of trees is really necessary to the overall garden design. In time they will bring dimension in areas where it is lacking, welcome shade in other areas and increased privacy. Most importantly a repetition of eucalypts and allocasuaurlnas throughout will help to unify the total garden.

For obvious reasons I had more concerns about planting trees on the view side of the house but as I watched the garden grow on this side I could see how the few trees, now 5 and 7 years old, and mainly planted within 3 meters of the house, break up the view and in doing so make it more interesting. In places eucalypts frame the view, or part of it - from other angles it is possible to see out through foliage or through multiple trunks of an individual tree or a closely planted group of trees.

So the exercise on the view side of the house became one of introducing trees into parts of the garden more distant from the house - between the house and the fence-line and along the fence-line. I wanted more shade in these sections of the garden so that I can enjoy walking there even on a warm sunny day. Trees will provide a vertical dimension that is missing, nestling the house further into the hillside.

With the garden sloping away quite strongly I also hope that trees planted along sections of the fence-line will, in time, direct the eye upwards where at the moment there is nothing to stop a feeling of insecurity as the eye perceives the garden tailing away. The fence-line planting should give increased privacy and a feeling of containment - a feeling that is important in making any person walking through the garden, or looking out over it, feel protected and secure. With a few trees and 2 metre high shrubs at the bottom of the garden, the distant view will generally be above the plantings. At the same time I am attempting to frame a mid-distance view of the neighbour's dam which has valuable links to my own garden ponds, by allowing one large space in the tree line.

Decisions about where to put the trees were made according to how they will change the view from the house. I used sticks in the ground and checked back at the house to see whether I was sighting them correctly because the position where a tree appears in the landscape changes with the viewing angle. On the south side of the house the slope rises up behind the house to the top of a hill. Here my main concern was to plant a scattering of local allocasuarinas - A.littoralis across the top of the block connecting them to older boundary plantings of this same species and a 5-year old forest of A.torulosa. Once again my aim is to find unity in consistency.

My treatment of eucalypts in particular has been the same as many other key plants in the design where I use repetition, overlap when bringing in a new species, and single specimens for occasional contrast and interest. The only difference, though, is that when I think about placement I try to think of the total garden, not just a bed or a section. From certain vantage points I expect the eye to be able to move through the tree canopy and travel beyond the garden plants into the borrowed landscape to increase the feeling of space in the garden. I have also chosen to intermingle and repeat eucalypts (E.leucoxylon, E.pauciflora, E.mannifera, E.scoparia, E.kitsioniana) that have a similar smooth trunk so that once again the eye will make the connections to produce a feeling of unity. The similar foliage of the allocasuarinas, means that different species can be used throughout the garden and once again I expect the eye will make the connections, the mind will find peace.

Now all I need is patience and good health to see if these newly planted trees create the expected effect when they are fully mature. In the meantime I continue to refine and expand on these ideas of using trees in the overall design and have already decided on 2 more locations where E.leucoxylon ssp.megalocarpa will replace dying shrubs. Please do not think that I am heading towards a heavily treed garden. I have a very large garden, about 0.5 hectare, and most trees are still planted close to the garden's boundaries. In this way I hope to preserve distant and internal views while maximizing the amount of sun and rainfall available to smaller shrubs.

From the newsletter of ASGAP's Garden Design Study Group, November 2002.

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