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.


Col said...

What is the best way to plant or position a strangler dog onto its host tree?

Patricia Gardner said...

With a lead. However there are simpler ways of getting rid of an unwanted tree!
(If by chance you didn't mean this question to be a joke, and "dog" was a misprint for "fig", please do get back to me.
I do like the joke, though.