Pragmatic Sustainability: Hungry wildlife

Winter was a tough time to grow veggies in the garden. The local wildlife, in particular the possums, were hungry. We have large numbers of possums in our area and our garden is on their nightly dining menu.

Possums are extremely well adapted to suburban areas, where gardens offer a wide variety of food. It's not just edible plants that come under their hungry gaze - roses and some other ornamentals are also high on their list of favourites.

Unlike the possums in the US, the ones in our suburban Melbourne backyard are pretty cute. Here are the 2 species we have visiting us:

Common Brushtail possum mother with baby via

Ringtail possum mother and babies via

However when you go outside at night and all you can hear is a chorus of chomping, they rapidly start becoming less cute. Mr PragSust chased three brushtails out of our loquat twice on one night. They don't take long to come back though.

This winter with food being scarce, the possums ravaged our garden, stripping the leaves off our edible plants. Bye bye silverbeet, parsley, loquat leaves and pretty much anything else green.

Fortunately we have a LOT of silverbeet so there was still plenty left for us.

They also started to eat the rind off the lemons and oranges. We were able to harvest most of those before it was too late. A tree full of nude lemons is a pretty sad sight.

Possum or rat damage to lemon via

The new shoots on the fruit trees are a BIG favourite of theirs, especially those of our plum and apricots. Needless to say, these trees struggle to fruit. The possums will even eat the bark off fruit trees. When we first moved in to our home we planted some small fruit trees, one of which was a mandarin tree. Within a couple of nights all the leaves on the mandarin had been eaten. I thought that was the end of it, but no, the possums came back the next night and ate all the bark off the poor tree. We quickly knocked up some chicken wire enclosures for our other little fruit trees and they survived the onslaught. Branches on the large avocado tree we grew at our previous home were systematically ring-barked by the little devils. Constant attention like this eventually kills the tree and I'd been out in the yard when large, ring-barked branches fell from the tree.

As well as doing plenty of damage in the garden, possums often like to nest in your roof-space, making a hell of a lot of noise, mess and damage. Their wee really stinks and leaves nasty stains on the ceiling. Possum wee on the garden furniture strips off any protective finish you may have applied and leaves them horribly sticky. Unfortunately, all of this comes from personal experience :(

Where we live it's illegal to relocate them. The trapping of common brushtail possums living in buildings is permitted. When trapped, possums must be released on the same property within 50 metres of the capture site. Licensed wildlife controllers are also authorised to trap possums but they will not relocate them to another site. Common ringtail possums remain fully protected and may not be trapped. In addition, possums are territorial - when one goes, another will quickly move in and take it's place.There would be an endless supply of willing replacements in our neighbourhood.

So what can you do about these pesky critters? Well here are a few suggestions:
Net the trees or totally enclose your fruit and veggie garden. We are increasingly using nets, however nets do tend to discourage bees so it's best to wait until pollination has been achieved.
Grow decoy plants. We use silverbeet with some success.
Spray the affected trees - use a mix fresh crushed chilli seeds, garlic, olive oil and detergent and spray it on the young leaves and early fruit. The drawback is that you need to keep re-applying if it rains or if there is a heavy dew. And sometimes it doesn't work - some possums seem to like chilli - a friend lost an entire bush full of chillies to possums. Good grief.
Dogs scare the possums from coming down onto the ground, but a dog that barks at possums all night will not endear you to your neighbours.

The Department of Environment and Primary Industries (DEPI) recommends the following course of action:

Build a floppy fence around the garden. Use 80 centimetre wide, heavily galvanised chicken wire, bury the bottom 20 centimetres into the ground and support the remainder on vertical lengths of flexible, high-tensile fencing wire. Bend the wire to curve the upper section outwards. When the possum attempts to climb the fence it will bend over and then spring back.
Use collars to protect fruit trees.