Friday, July 31, 2009

Strangler Figs

A strangler fig is a good choice if you have room for a big tree, and want it in a place where you already have a large but dead or dying tree - or perhaps just a large tree which you'd like to see replaced in the long term with something big, shady, and environmentally friendly - (some of our weedy camphor laurels or celtis trees, perhaps?)
Strangler figs can be planted in the ground, but grow very much faster if established higher up. In nature, they begin their lives high above frost level, usually in the fork of a living tree. As they grow, they send their roots groundwards. These roots may be invisible at first, inside the trunk of their host.
The photo at left was taken in a North Queensland rainforest, but you will see examples of the same process in our local forests.

Here is one which was interrupted by the felling of its host - but you can see that it's going to survive. It will be a very odd-shaped big tree, one day!

Assuming that the host tree remains upright while its house-guest continues to grow, it is eventually covered by the fig's roots, and dies. This may not happen before its time, however. There do seem to be some elderly host trees whose lives are extended, their weakening trunks supported in their old age by strong young figs. Meanwhile, the fig-host combination is an attractive and interesting thing, very appropriate as an ornamental feature for parks and large gardens.
Strangler figs are so strongly characteristic of our part of the world that they add an authentic touch to any assemblage of natives, particularly one with a rainforest theme.

A Hardy Local Strangler
Ficus rubiginosa
Known as "Scrub Figs", these are the toughest and most drought hardy of our local stranglers, happy in situations well away from the rainforests favoured by their cousins. They frequently begin life in exposed sites on an old dead trees, and are commonly seen in paddocks around Toowoomba. Many of them have been planted by farmers, who take advantage of standing dead timber to keep the young trees out of reach of browsing stock until they are large enough to provide shade for them.
Establishing stranglers is a simple matter of imitating nature, and planting them up high, out of the frost’s reach. Even where frost is not a consideration, high-planted figs always grow much faster than those planted in the soil. A small pocket of well-rotted leafmould or sawdust, and little bit of water at planting time is all they will ever need - though of course they will grow faster if they can be given more.
Some sturdy posts (such as old-fashioned house stumps, of the sort which support old-fashioned, high-set Queenslanders), can even be installed with figs planted in their tops. A hole the size of a 15cm pot is more than adequate room for them. What a clever way of getting a shady avenue of tall trees in a relatively short time.
We once recognised several local species of strangler fig, some growing on trees, others happily "strangling" rocks. They were known by various names including "Ficus platypoda" and "Ficus obliqua var. petiolaris". Botanists have now decided that these distinctions were rather artificial, and our local species are really all part of the same widespread genus, F. rubiginosa.
This comes as bit of a surprise to us, as "rubiginosa" means "rusty" - and our locals have no hint of rusty colour on their shiny green leaves. However, in the Sydney area the species does have rusty colouring on the undersides, and this is where the name was given to it - so however inappropriate it may seem, we're stuck with it.
As they grow, native figtrees fit themselves to the space available. In a crowded forest they grow tall and thin. In open, sunny spaces they develop broad, shady, umbrella-shaped canopies.

Figs are very bird-friendly trees, their dense canopies providing nesting sites, and their fruits, which can occur at any time of year, providing food for the fruit-eaters at all times of year. These were photographed at Gowrie Junction a few weeks ago.

Saturday, July 25, 2009

Woodland Clematis

Clematis decipiens (previously included in Clematis microphylla)
I have just spent a delightful afternoon with friends, rambling over a hillside at Gowrie Junction where this plant is flowering spectacularly.
We wanted to learn how to distinguish between the male and female plants - and found it easier than we expected.

The male flowers held their heads up and looked us straight in the eye

- and were crowded in masses all over the plants.

The female flowers were numerous, but definitely not in such crowds, on the female plants.

They hung their heads modestly, their silky tresses gleaming in the slanting sun. We could actually pick them from afar by the gleam.

This clematis, with its creamy-yellow flowers, is one of my favourite plants, and I am surprised that it’s so rarely offered for sale, and almost never seen in gardens.
It’s a relatively small climber.
A trellis about a metre square would be enough for one plant. Its woody stems never get thicker than your little finger. It is so dainty that it looks delicate, but is really one of our toughest plants, resisting our worst droughts, and frosts. (Don’t expect the same frost hardiness from the white-flowered coastal variety of this plant.)

The female plants go on to produce these lovely “old man’s beard” seedheads in summer. Males are needed for pollination, of course, so for the best long-term display a number of plants would be grown to ensure having both sexes.
This is a particularly good plant to grow on a fence, but it can also be set free in a shrubbery, where it will go almost unnoticed until it flowers.

Thursday, July 16, 2009

Vines Kill Trees

Don’t they?
People will believe the most astonishing things. I recently heard of this “reason” being trotted out as justification for killing some lovely native vines, which had been living inoffensive lives in a particularly beautiful patch of local vine thicket.
The man in question was so sure he was right, that he was surprised that his neighbours, the owners of this particular patch, were offended by his actions!
Sadly, however, there ARE vines which kill trees.
We see them in our local gullies, creek and river beds and sheltered valleys, smothering everything from giant trees to small shrubs. They prevent new plants from regenerating, so the whole area of bushland is eventually destroyed.
But not one of these killers is a native Australian plant. All the smothering vines that you now see blanketing so much of our bushland were introduced to Australia by our nursery industry as ornamental plants. No doubt they were seized upon by innocent Australian gardeners with glee, because of their cover-up qualities. What better thing to plant next to an ugly fence, a backyard dunny, or a tumbledown shed?
Many of them are pretty things, too. We still see them in gardens, occasionally, but of course no responsible person would grow one nowadays.
The most familiar of these killers, in our district, are cats claw (Macfadyena unguis-cati), balloon vine (Cardiospermem grandiflorum), Madeira vine(Anredera cordifolia) morning glory (Ipomoea species), asparagus vine (Asparagus africanus) and moth vine(Araujia sericifera). But there are plenty more of them out there, probably including some still selling in nurseries. A newly feral plant in this district is bridal creeper (Asparagus asparagoides) also known as florist’s smilax. No prizes for guessing how it came to spread around the country in the first place!
They all take to the bush with glee, preferring “disturbed” areas - a good reason for maintaining our local bushland in good health, with as little disturbance as possible and its full natural complement of native vines.
This was very good vine country, once, so any natural landscape would have contained a large variety of vine species.
And NONE of them would have been killing the trees!

Wonga Vines

Pandorea pandorana

Wonga vine is making a splash around the ridges at the moment. with its usual extravagant spring flowering.

A good many cultivars of this species sell in the nurseries. Their flower and leaf size varies, as does the length of flowering time. The flower colours range from yellow to white, with all shades of cream in between. Internally, they have red-streaked throats of varying intensity, and in some of them the internal red seems to have run in the wash, tinting the outside of the bell-shaped flower with pink.

However, it’s hard to beat the local native variety which can simply be grown from local seed. Its blossoms are almost pure white, with richly streaked throats.It flowers very heavily, with long-lasting flowers. 

The plants buzz with insects on every sunny winter’s day, and the little birds pursue them from their hiding-places in the dense tangle of the foliage.
These are rainforesty-looking vines, but it grow in our drier vine thickets, so are both drought and frost hardy (though very young ones appreciate a bit of coddling). They will climb trees (and trellises), but if they have nothing to climb they form mad, tangled shrubs. We often see them in this form in paddocks, where they provide excellent wildlife shelterLittle plants grown from seed have lacy, delicate-looking leaves with tiny, tooth-edged leaflets. They differ so strongly from those of older plants that they are easily taken for some quite different species. They are rather slow-growing in their first few years, so need to be placed somewhere in the garden where they can be given time to reach their full beauty.
A really good old wonga vine should be a local icon, the glory of every mature garden in our district!

Tuesday, July 7, 2009

Silver Croton

Croton insularis
Around the district, the crotons are in flower.
The flowers are interesting (to butterflies, as well as to us), but not actually particularly showy. With these plants, it is the scatter of bright orange leaves which are the main attraction. Every leaf turns bright orange before it dies, but unlike deciduous trees which use up all their glory in less than a month, crotons ration the display so it lasts all year.
New leaves are pale silver-brown, and the adult leaves all have silver backs, which show every time the trees is ruffled by the breeze. The bark is pale, too, so the overall effect is of a light-coloured tree.
These are very fast-growing small trees, suitable for the suburbs, and very useful for new gardens. When young they like a semi-shaded position and shelter from frosts.
They are equally happy in heavy blacksoil and our very lightest redsoil.
Though usually grown as single-trunked specimens, they can be pruned as a hedge, or coppiced (cut back to the ground) when they respond by producing multiple stems and re-growing as shrubs.

More Prickly Lixy

Alyxia ruscifolia

Since my post of last month, these plants have only become more wonderful. They always flower quite well, but this year they’re outstanding. At Gowrie Junction today my companions and I were finding the plants by following the perfume as it wafted downwind. It resembles jasmine.

The shrubs were a mass of flowers, with the orange fruits still hanging on, and this lovely plant had a good crop of lichen on it as well - a sign of a healthy environment.

(Don’t, of course, believe the rumour that lichens damage plants. They do nothing of the sort, and are so interesting and varied in themselves that their richness only adds another dimension to a garden.)
I was interested in the comment by reader Mick last month that he has some prickly lixy with black fruit, down Ipswich way. That’s a variant I haven’t heard of before.

Hoop Pine Babies

Araucaria cunninghamii
Hoop pines can have thousands of these babies, scattered under the trees, looking like little green dragonflies. (Double click for s closer look.) There is a great crop of them in the Boyce garden at present.
They won’t grow, these seedlings, because the roots of the parent trees exude a substance which eventually kills them off. Biochemical inhibition, it’s called.
Flindersia species (such as crows ash, Flindersia australis) can do the same thing to hoop pine seedlings. Crows ashes like to be the tallest trees in their own neighbourhood, and can prevent themselves from being shaded out by any too-close hoops. So, unfortunately, can those feral pines which escape from our forestry plantings or from private gardens. In this case, however, it is the introduced pines which are the aggressive colonists, preventing hoop pines from reproducing in what was once their own territory.
Allan Cunningham, after whom the trees are named, never did get to the site where Toowoomba now stands - but he saw it from a distant vantage point somewhere near Grantham, long before any white person reached it . He was quite excited to see his newly discovered Araucaria dominating the skyline. It must have looked something like this view at Canungra.

The Boyce Garden (corner of Range and Mackenzie Streets, Toowoomba) is the last tiny remnant of the rainforest he saw, and even its hoop pines were planted in the 20th century. It’s amazing how thoroughly we ex-Europeans have managed to exterminate whole environments, since our ancestors first settled in Australia.


Cordyline petiolaris
These plants are fruiting prettily out at the Bunya Mountains at the moment.
Despite their common name, they are neither lilies nor palms. They are in the agave family, and are closely related to the imported Dracaena plants which are so popular in gardens. The locals are much more environmentally friendly, of course.
They are wonderful in a shady garden for a cool green effect. They grow quite fast fast to about 2 metres in height, then, slowing down, can get as high as 7 metres (though this great height is fairly unusual, and the result of growing in low light and needing to stretch to get their fair share).
In spring they have generous panicles of lavender flowers, which are followed by these red berries.
Like so many of our local plants of the dry rainforests, they cope well with drought - but do look their best, and grow faster if given water and a bit of fertiliser
In the wild they grow under trees, and do well in a similar situation in a garden. Being narrow plants they are also very appropriately fitted into the narrow strip between suburban houses, particularly in situations where there’s not a lot of sunlight. They are effective in courtyards, or as indoor plants, sculptural lines looking particularly good with modern architecture.