Netting fruit trees
Whether it is a backyard fruit tree or an orchard, netting can provide a reliable physical barrier between a pest and a crop. Growers can use a range of netting options to protect orchard crops from damage by flying foxes, birds and even some insect pests.
Using the right type of netting will protect the fruit. Using the wrong type, or badly erected netting may still protect the fruit but it can also injure or kill animals including native birds, flying-foxes, possums and snakes if they become entangled. This is now recognised across Australia as a cruel and unnecessary cause of injury and death for a range of animals—both wild and domesticated—and a campaign is underway to encourage the use of safe netting and stop the deaths of thousands of animals each year.
Effective use of netting
Who’s eating the fruit?
The first step in netting a fruit tree is to identify the type of animal eating the fruit and whether netting will solve the problem.
Fruit can be damaged by a range of ‘pests’, and for netting to have any impact, it must create a barrier between the fruit and the animal trying to eat it. Netting is only an effective solution where the fruit is being eaten by larger birds or mammals like rats, possums or flying-foxes.
Bird damage is relatively easy to detect as they will be seen feeding during the day. Mammals are nocturnal but will leave clues like damaged fruit with teeth marks, scratchings on the bark, or a scatter of droppings under the tree.
The following guide will help identify what type of mammal is eating your fruit.
|Species||Indication of presence|
|Common ringtail and common brushtail possums|
Is it worth netting?
It is important to weigh up the cost of netting against the value of the fruit being grown. If netting is too costly, it may be better to consider some alternatives (see below), or accept that a small percentage of fruit will be eaten by wildlife. In times of drought when there is little food around for native animals you may even remove netting and sacrifice some of your fruit to help local animals survive.
Will netting affect how the fruit develops?
No. Netting allows fruit to develop while protecting it from possums, birds and flying-foxes as well as wind and hail damage. It can even form a better microclimate for a fruit tree to grow in and fruit to develop. The size of the mesh must be large enough to allow pollinating insects to reach any flowers on the tree and fertilise them. Avoid using shadecloth as it can make fruit go mouldy.
Netting safely for wildlife
Types of netting
Sturdy netting with a knitted mesh and a small aperture less than 5mm by 5mm, woven from strands 500 microns thick (minimum) will keep out birds, possums, flying-foxes and rats. White netting is best as it stands out against the foliage of the fruit tree. This will make it easier for flying-foxes to see and avoid. This type of netting will also protect fruit from sunburn, hail damage and fruit fly.
Suitable netting can be purchased from hardware stores, nurseries or specialist netting manufacturers.
Thin nylon (monofilament) netting should not be used as it is easily pulled out of shape by an animal climbing on it, causing the animal to become entangled. Once entangled, birds and flying-foxes become stressed, breaking bones and tearing wing membranes as they struggle to get free. The monofilament line can cut into the animal causing deep wounds and even stop circulation. Ultimately, these injuries can lead to shock and death, particularly if the animal is trapped for a long time. Entangled flying-foxes may also be mothers nursing young that are waiting at a nursery roost. These young will starve if the parent cannot return to the roost within a day.
When netting fruit trees, ensure that the net is kept taut. If the netting is loose or easily loses its shape, it is more likely to act as a trap for wildlife.
To keep netting taut, the first step is to build a frame over the tree to support the netting. This could be a box-shaped frame of PVC pipe or timber, or a number of star pickets or stakes that are located around the tree to form a frame for the netting, e.g. crossing three or four stakes to make a tepee frame. It is important that the frame keeps the netting off the tree and is sturdy enough for the netting to be pulled taut.
Tent pegs, or any heavy objects (e.g. bricks) wrapped in the ends of the netting, can be used to keep the netting tensioned over the frame and stop animals from getting under the net. Clothes pegs and tie wire can also be used to stop the net slipping and sagging on the frame to form traps. The more places that the netting is held in position, the more even the tension of the netting will be on the frame.
When estimating how much netting is needed, allow enough for it to be firmly attached to the ground.
It is important to have some way of getting to the tree to remove fruit. Either a flap could be cut into the netting or an overlapping section of netting built into one side of the frame to allow a person to slip in between them. Any openings in the net could be closed off with clothes pegs or by weaving a garden stake through the mesh along the edge of the flap (or overlap) and the adjoining section of netting.
The bounce test
Common brushtail possums can weigh up to 3.5kg, common ringtails 1.1kg, and grey-headed flying-foxes up to 1kg, and they can weigh down loose netting. For the netting to be effective, it must be tensioned enough to stop folds of net forming around an animal when it lands on or crawls over the net. Ideally, a flying-fox should almost bounce off the netting rather than sink into it when it lands.
Check netting at least daily. Animals could still become entangled.
Animals entangled in netting are likely to be injured and highly stressed, meaning any attempt to remove them is potentially dangerous for the animal and the rescuer.
If you find an entangled animal, without touching the animal cover it with a towel then contact the RSPCA Qld. They will put you in contact with a licensed wildlife rescuer who is trained to handle and care for wildlife. Read about what you can do if you come across a sick, injured or orphaned animal.
If you find a dead flying-fox, check to see if it is carrying a baby. If there is a baby present contact RSPCA Qld. Use a shovel to move the flying-fox and bury it deep enough so it won’t be dug up by another animal. If this is not practical, put it inside two garbage bags and seal them and place it in your wheelie bin.
Alternatives to netting
Different animals reach the fruit in different ways. If the problem is a possum or a rat climbing up the tree, then a sheet metal collar around the trunk may stop these animals reaching the fruit. If the tree is short enough for an animal to jump into the lower branches or to climb on to the tree from a fence or a neighbouring tree, a collar will not work.
If another tree overhangs a fruit tree, the branches can be pruned back so that it becomes too far for a possum to jump between them.
Covering individual fruit in paper bags can also work where the fruit can be reached easily and safely.