Tuesday, December 9, 2014

Grow Cassias for Butterflies


If you grow native cassias, you will always have yellow butterflies in your garden.

Butterflies like to hang around their host plants - the plants which have the right kind of leaves to feed the babies of their particular species - and cassias are hosts to a number of butterfly species.

Cassias have been subject to one of those name changes that botanists inflict on us, periodically. They are officially Senna species these days, though most people still call them cassias.
 

The Crows Nest Community Nursery has two good local species of shrub-sized Senna for sale at the moment - Brush Senna and Brigalow Senna. At an affordable $2.50 each, it is a great idea to put in a group of these pretty, sun-loving plants, making it easy for butterflies to notice your garden and move in. 
(If you can’t manage to get out to Crows Nest nursery on a Thursday morning, to see their large selection of local native plant species, you can always order plants from them by ringing the nursery on Thursday mornings on 4698 2990, and arranging for pick-up and payment in Toowoomba.)

The butterflies you will attract, by planting native cassias, are likely to include

the small grass-yellow,

the large grass-yellow
 
and the even larger lemon migrant
 
and yellow migrant.

Native cassias also seem to bring sunshine into the garden, with their summer-long display of bright yellow flowers.
They are always aware of the sun, these plants, closing their leaves at dusk, and opening them again in the morning.
Sennas are tough, drought hardy plants. Our local species also tolerate all but the hardest of our local frosts. Their lifespan is somewhere between four and ten years. Plants that are pruned, fertilised and watered once a year after flowering (in autumn) live the longest.
They will grow in full sun, where they make dense screening foliage. They are also happy to fit in politely between other shrubs, never overwhelming them, but fitting their flowering branches into the gaps.
 

These Senna coronnilloides are sharing the dappled sunlight under some trees with some wilgas.

New plants are easy to grow at home from seed.

Put them into a coffee cup, cover with boiling water and leave to soak overnight, before planting those which have swelled.

Brush Senna
Senna acclinis

You get double environmental points for growing this local plant. Not only is it a butterfly host. It is also a threatened plant, having lost most of its rainforest edge habitat through clearing. A few plants can still be found growing wild on the western edges of Toowoomba, at sites such as Kingsthorpe Hill and Birdwood Sanctuary, but it is rare to find them in the district nowadays.
It is occasionally mistaken for the Easter Cassia (Senna pendula var. glabrata), a South American plant which fell out of popularity in gardens because of its tendency to grow to large, too fast, too leggy and too weedy-looking. It has never disappeared from the district, though, as it has jumped the fence to become an environmental weed. It may come up in your garden whether you want it or not. The brush senna is a more civilised plant, with a longer flowering period.
It grows to between waist and shoulder height (depending on whether or not you have pruned it), and makes a dense screen.
It may self-seed to some extent, if you are lucky, but a more reliable way of making more plants is to grow them from seed.
(If seedlings come up, and you are not sure whether you have this plant or Easter cassia, look carefully at the edges of the leaves. Easter cassia’s leaves have a narrow gold line around the edge.)


Brigalow Senna
Senna coronilloides

This equally desirable plant loves the heavy black soil to the west of the Range, but is happy on all soils.
Its fine leaflets are blue-green.

Friday, November 21, 2014

Butterfly Season

With the hot weather, we move into the full butterfly season, and what a beauty we’re having this year!
I suppose you have all noticed that this is a big year for caper whites (Belenois java teutonia)?
This is the butterfly with the fairly plain wingtops, white with black edging,


and the beautifully marked underside which you only notice if you look a little more carefully, or see one at rest.

I don’t think anyone knows quite why they sometimes have a spectacular year like this. We haven’t had one since before the 2011 floods, so perhaps they do better when the weather is dry.
People speak of them “migrating”, which suggests a purposeful journey with a planned end in mind. What they are really doing seems to be more of a random radiation. Perhaps they have exhausted their local host plants and are simply flying away in hope of finding more. They turn up in great numbers in the southern states where the host plants don’t occur naturally. There manage to find the few cultivated specimens, where they can be seen flying in a whirling mass around the plant. The males and females fly in separate migrations, but obviously succeed in meeting up, as they have been seen laying eggs in Victoria. (If they can’t find a caper plant, they lay on unsuitable plants, and the caterpillars die.)
They also fly out over the Pacific Ocean in their many thousands. Odd specimens have been known to turn up as far away as Samoa.
The butterflies breed on our local native caper plants, Capparis arborea, C. mitchellii, C. lasiantha and C. sarmentosa. Like most local butterfly host plants, gardeners rarely plant them, so the butterflies breed in the country and can only be enjoyed in our towns because they are strong flyers who will often drop in for a refreshing sip of nectar in our gardens. (Butterflies with less strong flying skills and migratory urges are disappearing from our urban areas, as they just can’t make the flight from the increasingly distant breeding sites.)
Most of our local native capers grow on country roadsides. They are prickly plants, so are grown only by butterfly enthusiasts, and tend to be cleared from farms and acreage estates by owners who don’t want to deal with the prickles.

They can also be completely defoliated whenever the butterflies have a big breeding year. They bounce back to beauty and good health afterwards, with all the freshness of a well-pruned plant, but the only people who grow them are those who value the cloud of lovely butterflies more highly than a high standard of year-round perfect beauty from their plants.
Roadsides are potentially subject to clearing for road-building, as our population increases, as well as “beautification” by those who prefer a well-mown, neat and tidy road verge to native vegetation. Depending on your personal aesthetic and philosophical viewpoint, a natural roadside environment is a rich and  environmentally productive ecology, or an ugly “hotch potch”. Unfortunately, destroying a patch of biodiversity is very, very much quicker and easier than replacing it, so the people who think nature needs tidying up, and are prepared to do something about it, have a disproportionate  advantage, when it comes to living in their preferred Australian landscape type.
The long-term future may hold fewer of these spectacular caper white population explosions. Let’s enjoy them while we have them.
For more on this butterfly and its host plants, see my posts for November 19, 2009 and December 4, 2008, or simply type the butterfly’s name into this site’s white search box at top left.






Friday, November 14, 2014

A New Way of Identifying Local Plants

It’s always been a problem.
You see a pretty tree in the local bush, or rainforest, or on your new block of land. You want to find out what it is, but nobody seems to know.
There’s a new tool that has just been released this week, that helps with a big chunk of the problem. It is an interactive identification key, on a USB, called:


It’s available from http://rainforests.net.au or http://www.rainforestpublishing.com.au , where you can also see some good illustrations showing what’s in the program.
The plants it covers are trees (including fern trees and palms), shrubs, climbers, and mistletoes. The definition of “rainforest” is very broad. All our local dry rainforest and scrub plants are in there, even those which are technically of "rainforest type", but grow in obviously non-rainforest situations out on the Downs. You’ll find wilgas, for instance.
The program costs $80.00. My first thought, being a frugal body, is that it is somewhat expensive. However, I had a second thought which is that it contains so very much more than could ever be put into in a single book that’s it’s a bargain. For instance there are over 12,000 photos!
The best thing is the key itself. My experience with conventional plant keys is that I can get lost somewhere in the pick-a-path process. This key, having the advantages of computer technology, lets you arrive at an ID from many different angles.
The keying-out process begins with the total list of plants, all 1139 of them, and every time you add a bit of information, it gets shorter, until you are left with the answer to your question.
First you put in what type of plant you have (tree, climber, palm, etc). At once, the list is shortened as other plant types are subtracted from it.
Then you might put in that your mystery plant has pink fruits. All the plants without pink fruits disappear from the list. Put in a few other characteristics that are obvious to you - maybe the geographical area, the size of the fruits, and the length of the leaves, and you may even end up with just your target plant left on the list already!
If you haven’t got there yet, there are loads of other questions you can answer to work towards an ID. At first some of these can look daunting. Is the leaf elliptic, ovate or lanceolate, for instance? What do the words mean?
No worries, clicking on a little icon next to the words brings up an illustrated description of all the leaf shapes, so you can easily find the word that best matches your plant sample.
The plant descriptions are also a help. Each plant name in the list has little icons beside it.
Clicking on them brings up a written description with photos, and a black and white sketch showing important identifying features. The pictures are a help when you have got the list of possible plants down to the last few, but can’t decide which one is your unidentified plant.
The other great thing is that there is a species index. You click on a plant name that interests you, and by the time you’ve read the description and looked at the photos of the whole plant, plus close-ups of the trunk, flowers, fruits, leaves (both sides) and so on, you really feel you know the plant.
Great stuff!

Monday, November 10, 2014

Cuttsia

Cuttsia viburnea
Now flowering - and what attention-grabbing flowers these are!

Found in damp gullies and close to creeks, in rainforest understorey, they stand out in the shade (or semi-shade), drawing the human eye. The strong honey scent of their nectar-rich flowers also attracts the attention of many insects, which in turn brings the birds that come to feed on them.
If fertilised, the flowers produce heavy seed crops in their little capsules. However,  as with many bisexual-flowered plants, Cuttsia plants are not self-fertile. Separate timing of the maturing of their flowers' male and female parts means that the flowers of isolated plants remain unfertilised, despite visits from many suitable pollinators.To produce seeds it must grow close to a friend or two.

A solitary plant makes a lovely garden specimen, but seed production matters if we are trying to re-introduce lost ecosystems or reproduce something like a natural environment in our own gardens. Don’t overlook the possibility of planting several quite close together if space is limited. This would result in something resembling a multi-stemmed large shrub or small tree.
Cuttsias grow best where there is constant soil moisture. Where this can be provided, this is an excellent plant for an understorey situation or a shady corner. Established plants do tolerate some drought, but would need to be helped along if the dry spell is prolonged.
They are claimed to be frost hardy.

There have been a few attempts to give this plant a “common” name. Some people call it elderberry (but it’s not an elderberry, and Australia has several genuine elderberry species which might even be growing side by side with this plant in the wild). Others call it native hydrangea (but it isn’t related to hydrangeas, and doesn’t resemble them much, as you can see). The name “native hydrangea” is more commonly used for the closely related Abrophyllum ornans, so like “elderberry, is not a particularly practical one. Others call it honey flower, which is very appropriate considering its strong nectar scent. Unfortunately, if you say “honey flower”, people are more likely to think you are speaking of another Australian plant, Lambertia formosa. Falling back on the botanical name, as we have done for grevilleas and quite a few other Australian plants, seems the best solution to achieving a user-friendly name for everyday use.

Friday, October 3, 2014

Garnet Lehmann Park

A comment has just been sent to my blog about the fight to prevent the Toowoomba Regional Council from removing trees in this local park. I feel it needs a proper reply, but sadly it might not be quite the response that the anonymous writer was hoping for.
(See it if you wish, by using the search box to find the article on the Toowoomba Tree, and opening the comments.)

I agree with the writer that Toowoomba's progressive tree loss is a serious concern. I believe that many Toowoomba residents share this concern, and that it is worth everyone’s while to represent to our council that we value Toowoomba’s status as a town which appreciates its trees.
However, flood damage downstream from the Garnet Lehmann Park is also a concern. There will never be universal agreement on how best to deal with the problem, but I do give the TRC council and its staff the credit for considering the options and I concede their right to make a decision. It’s far easier to criticise decisions than it is to make them, especially in cases like this where there was no easy right decision.

I suspect that the defenders of the Garnet Lehmann Park trees are now losing much of the public sympathy that they once had,  by the refusal of some of their more vocal members to accept that “the fight” is lost and that further protests are not going to be productive. They also seem to be slow to perceive that the only fight they have lost is the one to have all the trees retained.
It would be so good to see them move on, (and perhaps some of them have. I hope so.) What a pity, if a great group like this loses all its momentum while there are very real and worthwhile things still to be done. They have lost one battle, but they could still achieve much, if only they keep the fire in their bellies.

Some projects could include:

1. Ensuring that TRC does indeed carry out its promise that Garnett Lehmann Park will become an ornament to our city. This could take some time, and would require a group that would be prepared to continue its activities for years to come. It’s never easy to be a stayer, but I feel sure that there are people in the group who have what it takes to persist!

2. Contributing to the new planting plan for the park.
Is there a planting plan already in the pipeline? Does the group know what tree species are being proposed? Are these species just ornamental ones, or do they have environmental value? If they are Australian plants, are they a random selection of doubtful ecological worth from all over the country, or are they local natives which will improve the opportunities for survival of Toowoomba’s wildlife. (Our local butterflies, in particular, are in real trouble within the city - if they can be found at all - because of the lack of host plants). Has the group a role to play in suggesting suitable plants to TRC, and perhaps in supporting TRC’s environmental nursery (the Crows Nest Community Nursery) where volunteers struggle to cope with the task of propagating enough plants of local native species for all the environmental groups who would like to be planting them (ironically including TRC itself).

3. Should the group be pushing for something more appropriate than Eucalyptus trees to be planted in the park? TRC has a valid concern that Eucalyptus trees can create public risk problems because of their tendency to drop limbs as they get older. To restrict planting of Eucalypts to a minimum, in safe locations, would be a reasonable council policy considering the expected high rate of park usage as our population increases. Eucalypts planted in the city could have a short lifespan. Future councils may decide to remove them for safety reasons, which would put the poor old park back to square one yet again.
Others dislike the Garnett Lehmann gumtrees for environmental reasons. East creek would have originally had rainforest vegetation, so the gumtrees are interlopers, environmentally speaking. Even many of Toowoomba's "naturally occurring" gumtrees would be invaders that have moved into a niche created as our forebears cleared original rainforest. Gumtrees do this.
When Alan Cunningham climbed Mount Hay and became the first white person to record Toowoomba’s native vegetation, he commented on the Araucarias (hoop pines)) that dominated the skyline of the Great Dividing Range where Toowoomba now stands. What an opportunity the city now has, to create magnificent plantings of these lovely trees as it revegetates our detention basins.
Equally our local fig species are not seen in the city enough. These are large rainforest trees, only suitable for planting in parks now that ever-smaller residential subdivisions are the city's most likely future. Our grandchildren will be grateful if the figs are planted now, to create wonderful spaces like New Farm Park in Brisbane.

Native Fig (Ficus rubiginosa) in Meredith Crescent. One of the very few remnant trees from Toowoomba's original rainforest.

All our other local rainforest trees are in much more trouble than Eucalypts, so pushing for a park with a shady green canopy, showcasing as many local rainforest species as possible, would be a very worthwhile environmental project indeed. It would also help Toowoomba develop its own character, something that has become a little frayed at the edges of late as development has pushed towards a look that could be anywhere in the country.

4. Could the group be widening its scope to include pushing for TRC to budget  for the city’s other detention basins to be beautified and made more environmentally friendly?

5. Could it also be adding its weight to other local projects concerned with defending the city’s trees?

Yes, is sad to lose the trees in the Garnett Lehmann Park. It is sad to lose any tree! But for those who are still protesting, can I appeal you to turn your energies towards the battles that can be won, rather than continuing to waste energy on a lost cause.

Saturday, September 20, 2014

Brookvale Nursery

 The Carnival of Flowers is on, in Toowoomba this week.
There are lots of interesting things to do in town, of course, but this afternoon my husband and I decided to head out to Oakey, to see the display that Robyn Weick has put on at her new nursery.

The nursery only opened in January this year, but Robyn tells me they are already getting plenty of customers, including people who remember buying Australian plants from her father Lance Cockburn, when he ran the Brookvale Park Botanic Garden.

Robyn  and her brother Trevor have put together all sorts of interesting material for the display.
 
 Australian natives are strongly featured, as those who know Robyn and Trevor would expect. They have a great variety of cut flowers dispalyed in vases and in pots. There is also a good collection of Landcare and other environmental material. I did like the rather beautiful life-size models of that pesky Tilapia fish that's making a nuisance of itself in our local waterways.

Brookvale is a general nursery, but Robyn’s greatest interest is in Australian plants. She has a wealth of expertise on drought hardy species, and on suitable plants for growing in black soil. This nursery is a good place to buy emu bushes (Eremophilas), which are among the showiest, and most drought hardy of our Australian shrubs.

To find it:
  • Take the 30min drive from Toowoomba, west through Darling downs scenery, to Oakey.
  • Turn right into the town. (Don’t follow the highway round the bypass)
  • Follow the main route through Oakey until you are parallel to the railway line.
  • Brookvale Nursery is on the right, between the road and the railway, opposite Black’s Toyota.

Well worth a visit, at any time, but especially in this Carnival week.

Sunday, July 20, 2014

Bellfruit and the Fire Ecology.

Codonocarpus attenuatusThis is a surprising plant.
Its soft leaves make it look a rainforest species, but this may not be the case.
There are records of it being found in rainforests. However if they were seen when not fruiting, it’s a fair chance that the plants were actually bellfruit’s rare and endangered relative, Gyrostemon osmus, which was generally unknown until it was studied and named in 2005. It looks very like bellfruit, but has seed capsules that open along a dorsal split, unlike bellfruit capsules which drop their seeds out of the bottom.
The remainder of bellfruits's relatives, both Codonocarpus and Gyrostemon species, are plants of the desert or dry country out west.
Bellfruit itself is “Mr In-between”. Found in coastal and sub-coastal sites, it hangs about on the edges of dry rainforests and in disturbed areas hoping for fire to help its seeds germinate.
Australian ecosystems can be broadly divided into two groups – those (like rainforests and vine thickets) which are damaged and reduced by fire, and the “fire ecologies”, which depend on fire for good health. The latter are populated by plants which thrive with regular fires, and may even depend on them for the species’ long term survival. If the rainforest specimens are all actually Gyrostemon osmus, then we can place the true bellfruit, Codonacarpus attenuatus on the "fire" side of the fence.

The plants above, which I photographed a few days ago, were in a typical site. It is a large council-owned reserve in the Merritt’s Creek Road area which was covered with fairly open vegetation until it was given a clean-up burn in 2010. The result, in a mere four years, is this extremely thick growth of wattles Acacia neriifolia (another fire-loving plant) and bellfruit (centre plant with light grey trunk). Loving the fire, they came up like hairs on a cats' back from seed lying dormant in the soil.
The scrub is now about 6m tall. Crowding has resulted in tall thin plants with bare trunks and dense leafy growth at the top only.
Not all the bellfruit trees in the scrub have seeds on them, because the species has separate male and female plants.

                                                                                                                       Photo by Dougal Johnston
There are, however, plenty of male plants to ensure fertilisation of the female plants. They were heavily laden with their little green "bells". As the species is wind-pollinated, there is always a chance that having too few plants in the area might result in uneven pollination, with pollen failing to reach all the female flowers. This is clearly not the case there!
Bellfruit trees are not often grown in gardens, largely because they are not often available for purchase. Seeds are difficult to germinate, but are known to do better if soaked in smoke water.

Gardeners would need to put in several plants, to be sure of having specimens of both sexes, if they want to get the ornamental "bells".









Specimen plants grown in the open are likely to be as little as one third the height of the plant shown at left, and to have canopy almost to the ground.





















In gardens, a useful planting style can be to put a small group of bellfruit close together. This can result in plants (of both sexes) forming a united canopy, looking rather like a multi-stemmed large shrub.

Like many other fast-growing pioneer trees, bellfruits probably have a relatively short lifespan.