Wildlife and Food Gardens

A friend recently commented that, because her home is surrounded by bush, a vegie-garden at her place wouldn't stand a chance.  That comment made me realise it was time to devote a blog post to how people who live in the bush or in rural areas protect their food-gardens.

Most people who live in rural and bush areas realise that the land they live on would have been or still is part of the wildlife's habitat and that it is therefore not unreasonable to share with the wildlife some of the food grown on that property. One person commented that they get so many apples each season that they are quite happy share the crop with the local possum family.  However, when sharing your crops with wildlife means that you get nothing after mum, dad, children, uncles and aunties of the Brushtail family have had their fill, it is time to establish some boundaries, literally.

Your uninvited eaters may be diggers, such as rabbits, potoroos or bandicoots, in which case the only proven method of keeping them out is to have a wire fence which, just below ground level, extends outwards horizontally to around 200mm outside your fence line.

Your uninvited eaters may be possums, which, some people report, can jump up to 1.2 metres vertically, so fences meant to keep them out need to be higher than that.

Your uninvited eaters may be wallabies, for which fences will have to be extra sturdy and ideally electric, so animals are discouraged from using their force to crash through.

Many landowners put in place fences that combine all the above mentioned features arguing that it is best to spend the money and the time to put up a fence that will do the job once and for all.

Your uninvited eaters may be birds.  Further down this blog post you will find examples of enclosures and cages that keep them away effectively.

First some general remarks about fenced food-garden areas:

1. It is best not to build one fence around your whole garden, but fence individual food-garden areas, so if one area is ever breached, your whole garden is not exposed.
2. Make your fenced food-garden area(s) bigger than what you need at present, so if you want to expand later on you can do so without having to put in more fencing.
3. Locate your food-garden areas so that there are no trees or bushes within a metre of your fence or overhanging your fence line. To achieve this you may have to remove trees or bushes.  The best fence becomes a waste of time and money if you don't take this seriously.
4. Gates are other notorious weak points of fenced garden areas.  Minimise opportunity to enter by giving each fenced area no more than one gate.
5. Never use barbed wire.  Each year many animals face a cruel death or permanent injury from entanglement on barbs.  Barbed wire is really not needed.

'Floppy fences' are used successfully by many people.  Here is an example of such a fence, built by Rachel at Molesworth:

Floppy fences are not the most beautiful type of fencing, but what is more important, looks or produce?

A good floppy fence works as follows: as a possum (or quoll or ..) attempts to climb the overhang, it bends down.  The possum lets go and falls to the ground.  The floppy top springs back to its original position, ready for the next attempt.

In the photo above star-pickets are positioned against fence posts and used to extend the wire-mesh beyond the fence line.  Horizontal wires re-enforce the wire-mesh across the star-pickets, but not the wire-mesh beyond the end of the star pickets, so the top become 'floppy'.  Rachel commented that, if she would build this fence now, she would make it 1.8 metres high.

The wire-mesh in most floppy fences springs back to its original position because it has a 'high-tensile support wire' (see diagram below):

Tom and Ilse built a floppy fence on their property near Snug.  The photo below shows their simple but effective interpretation of the high-tensile support wire:

The choice of wire-mesh is important.  For the floppy top part choose the smallest gauge mesh that holds itself up, but is flexible enough to spring back.  The mesh in the photo has 50mm x 50mm holes and is 1mm thick.  It 'flops' effectively.

Posts are another point to consider.  Some people use star-picket posts and they are fine, but treated pine posts, properly anchored, allow much better tightening of wires.

'Proper posts' are of course easy entry points for climbers.  In the diagram above look at the 'shape of wire mesh for corner insert'.  Here is how Tom and Ilse interpreted this:

With the help of high-tensile support wires, the mesh is curled around this corner post so it becomes impossible to reach.  It is best for posts not to be higher than the wire-fence.  A similar system can be used to protect individual fruit trees.

It is easy to make mistakes when designing the gate.  For a start, how about making it wide enough so your wheelbarrow will go through it.  So simple ....  if you think of it ....... at the time!

Gates are easy entry points for wildlife, especially if, umm, well, you leave them open.  So give your gate a good spring, so it always closes behind you, but one that you can remove, so if you need to go in and out with your wheelbarrow many times for a particular job, you can take it off, just temporarily.

The gate below has been covered with galvanised iron, nice and slippery and 'unclimbable'.  The ends of the sheet have been bent back so the edges are not sharp and again provide no grip.  Also have galvanised iron sheets either side of the gate because these spots can also create access points.

The gate has a threshold so no one can dig under the gate.  Talking about digging: at ground level, all around the perimeter, the wire-mesh has been extended so diggers are discouraged to dig their way in:

Rosalie had another solution: she has so many rocks in her soil and dug out so many over the years that she created a border of rocks all around her enclosures ; a good application of free resources.

Now about adding electric wires.  Some would argue that a good floppy fence does not need them, and they may be right.  Others feel that the added discouragement is definitely worth it.  Please realise that electric wire can fail (shot-circuiting in wet weather, power failures), so only use it as an add-on.

If adding electric wires, it is critical that, horizontally, they are no more than 10cm from the fence itself, so the animal touches the electric wire while touching the fence ('earth') and therefore gets a shock.  Rachel recommends an electric wire more than 1.2 metres from the ground so possums can not jump past it.  Tom and Ilse's food-garden fence has two wires, one near ground level, and one on top of the floppy end.

Here it shows a simple and inexpensive method of attaching the electric wire to the fence:

An underground power line goes back to the house to a converter that transforms 240 into 6000 volts.

Now let's look at some other food-garden protection solutions:

If you only have a few food-garden beds, simple inexpensive poly-tunnels with bird-netting can do the trick if your aim is to keep birds and the occasional mildly-interested ground-animal out.  Determined possums or wallabies could completely trash this structure, but for this owner, in these circumstances, the poly-tunnel is a cheap effective solution.

A poly-tunnel on a raised bed can be really effective as rabbits and others don't like leaving ground level because it makes them highly visible.

You can find more about simple poly-tunnels at http://www.youtube.com/watch?v=Dl0POCqCLtE

On her property near Molesworth Rachel has taken the concept of poly-tunnels a whole lot further:

This is a twenty metre by 5 metre cage

These structures are very sturdy, their shape makes them not wind-prone and with small mesh and mesh dug in as discussed above, they can provide complete protection against all wildlife.

On her property Rosalie has converted chook-pens and dog-kennels into nice big totally protected food-garden areas:

In this case wire-mesh was used for the roof.  This means snow will not make the roof sag or tear.

On her property near Richmond Tara used bird-netting for the roof of a large enclosure and that works fine because she would never have a snow-covered roof.

At their property at Howden Dirk and Pauline used steel-reinforced fabric netting (see photo below). It is strong. It can be used in parts of Tasmania where netting might tear under the weight of snow. Just  put support beams a bit closer together than you normally would.
This steel-reinforced netting comes from a company called Haverford. On the Haverford-website you will find various sizes, as well as by the metre. Order it online, and it will arrive via courier.

In addition to the netting, Dirk and Pauline have a layer of fine wire mesh covering the bottom metre of all cage walls. The mesh continues underground and was bent outwards, away from the structure, so wildlife can not dig into the enclosure. Another very good reason for having the metal wire at the bottom is that it would be very easy to damage the netting with a mower or whipper snipper. The metal mesh prevents this.

At Acton Russell built a really huge and very effective enclosure for his fruit trees and berries.  It is 11.4 metres by 20.4 metres and 3 metres high.

Here is a close-up of one of the posts in the centre of the enclosure:

And here is one of the corner posts:

The posts were concreted in .6 metre deep holes.  That should do fine, you would think.  Russell needed a whole team of people to put on the enormous net with him.  When the net was sufficiently stretched he noticed that the tops of the corner posts had moved slightly towards the middle.  It is easy to under-estimate the forces at work in a large structure like this.

At Sandfly Russell built in stages a segmented cage down a slope. The cage is robust enough to cope with a layer of snow on its roof.  It is covered in fine metal mesh that has holes big enough to let insects through.

Here is how it looks on the inside: (notice the paving throughout)

Other measures to keep wildlife out are keeping a dog inside your fenced area, giving it a border of fragrant plants or hanging shiny objects around your garden.

Fencing food-gardens is a really big subject.  I tried to provide an overview that shows people that food can be grown successfully in bush and rural areas.  Building the necessary structures can be a time and money consuming business, but once done properly, will be very rewarding.  Wonderful tasting produce will make your investment more than worthwhile.

Many thanks to Tom and Ilse, Rachel, Russell and Rosalie for their contributions to this blog post.  

Anyone with info or comments that can further improve this blog post ......

Anyone with other solutions that keep wildlife away from food-gardens ........

Anyone with questions regarding this subject .........

People interested in seeing these solutions up close and personal ........

please email Max at foodgardengroup@gmail.com and I will refer you or provide further info.

There are a few web-sites that I found helpful when writing this blog post.  Have a look at

http://transitionderwent.com/be-the-change/save-money/grow-your-own/fencing-critters-out/ 

and

http://www.pindariherbfarm.com/selfsuff/flopfenc.htm