Castlecrag Community

The Crag No. 150, April/May 2004: Trees in Castlecrag

The Crag No. 150, April/May 2004: Trees in Castlecrag

“The reports of my death are greatly exaggerated.” – Mark Twain

Last year’s drought and this year’s water restrictions mean that many of our gardens, and the bushland reserves, are stressed. As well as having less water in the soil, trees are being targeted by our native fauna, which includes possums and many native insects. They are looking for a quick meal but finding that there is less to choose from this year.

The way in which native trees respond to these conditions is by survival strategies that they have evolved over eons. Trees reduce their water demand during the tough times by losing leaves, or their smaller branches might die.

In nature, after the stresses are past, trees often recover. Typically, new shoots that have been dormant in the trunk and at the base of the tree spring back to life when the drought ends, much as we see trees recovering after bushfires.

Sadly, we have been seeing a lot of very grand trees chopped down in recent months because they look dead. Given time, they might have recovered.

The most valuable plants in any landscape are the mature trees. These form the basic structure of the bushland and gardens, and will take decades to replace. We are lucky in Castlecrag that many of our special garden trees – Angophoras, Sydney Peppermints, “Old Man Banksia” to name a few – are relics of the original bushland. They keep the links and wildlife pathways from the bushland through the built-up parts of Castlecrag. Some of these trees are a hundred years old and more. Replacing them will take longer than our lifetimes.

At present, the possums in our area are feasting on these new shoots and making it hard for some trees (such as Angophoras) to recover. We love the possums, but this is the time to exclude them from favourite trees by a possum guard (see below).

Of course, trees can become stressed because of other causes: for example, changes in drainage, too many nutrients, or insect attack. But care for a tree is worthwhile, and consult an expert if in doubt. The chainsaw should only be a last resort!

So . . . here are a few ideas:

1. Even if a tree appears to be dead, give it a little time to see if it might recover. Seek the advice of an expert arborist.

2. If dead branches might be dangerous, have these removed carefully, but keep the living parts of the tree to recover.

3. Stop possums eating the new regrowth shoots by possum-guards around the trunk.

4. Plant some new native trees to replace the ones which might have been lost in years past. We all enjoy our native birds, so every garden in Castlecrag should have at least two native trees!

AN EASY POSSUM GUARD

This works well if there is no direct branch-to-branch contact with other un-guarded trees. You might need to put guards on several trees.

Wrap a sheet of heavy flexible plastic around the tree trunk and secure it with grey duct tape. The plastic needs to be heavy enough that the possums can’t dig their claws into it. When wrapped around the tree it needs to be about half a metre high. We used a sheet of clear polypropylene – very flexible and easy to handle; we bought it at Eckersley’s Art Supplies, 21 Atchison St., St Leonards for $9.

We placed a guard on an Angophora that had lost all leaves and appeared to be “dead”. Within two weeks, new shoots 20cm long had grown from the trunk. They will become the new branches. We plan to leave the guard in place for at least six months, until the new branches are strong.

Lorraine Cairnes, Castlecrag

LIVING WITH POSSUMS

Possums are native marsupials. In the bush, they feed on leaves, buds, flowers and fruits. Brush-tailed and Ring-tailed possums are found in Castlecrag, and some of their rarer relatives, including Sugar gliders.

Possums have adapted well to contact with people. Most of us have learned to get along with these beautiful creatures, whose home we now share. Visitors from overseas are entranced to see such appealing wildlife so close to the city.

However, at times this contact can be noisy and messy – particularly if the possum takes up residence in the roof of your house!

In the next issue of the Crag we will provide more information on living in harmony with possums. In the meantime, remember that possums are protected in NSW and catching possums without a licence is illegal in NSW.

Licences to trap possums on your property are issued by NPWS free of charge from any NPWS office. A pest control company, licensed by NPWS, can trap the possum for you, or traps are available for hire from some pest control companies.