Shade Cloth Method. Illustration by Louise Saunders |
Using the right type of netting will protect your fruit. Using the wrong type, or badly erected netting may still protect your fruit but it can also injure or kill native birds, flying-foxes and possums if they become entangled.
With a little forethought and care, backyard fruit trees can be netted so you can enjoy fresh fruit and wildlife too.
Effective use of netting
What's eating the fruit?
The first step in netting a backyard fruit tree is to identify what's 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 birds are active during the day and more likely to be seen while feeding. Mammals are nocturnal but will leave clues behind in the form of damaged fruit with teeth marks, 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
Flying-foxes
- pellets of mouthed fruit pulp
- 'squirts' of droppings
- partially-eaten fruit (may show scrape marks made by small front teeth and large canines)
- fruit dropped on ground away from tree
- partially-eaten fruit showing a series of scrapes (may show scrape marks of six front teeth, forming a groove about 10 mm wide)
- fruit disappears (can be carried away by brushtail possum)
- pellet-shaped droppings (around 10-15 mm long) under tree
- partially-eaten fruit showing a series of small scrapes (may show scrape marks of a single pair front teeth, each about 2 mm wide)
- small pellet-shaped droppings less than 1 cm long
It’s important to weigh up the cost of netting against the value of the fruit being grown. If netting is too costly, you may want to consider some alternatives (see below), or accept that a small percentage of fruit will be eaten by wildlife.
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.
Alternatives to netting
Tree collars
Different animals reach the fruit in different ways. If your 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 won't work.
If another tree overhangs your fruit tree, the branches can be pruned back so that it becomes too far for a possum to jump between them.
Shadecloth
A 30 per cent blockout shadecloth can be pegged or tied over a fruiting tree to protect the fruit. Shadecloth is a low risk to wildlife and still allows fruit to ripen. It should be hemmed so that there are no frayed ends for animals to get caught in. When fruiting is finished, the shadecloth can be stored away.
Paper bags
Covering individual fruit in paper bags can also work where the fruit can be reached easily and safely.
Netting safely for wildlife
Teepee Method. Illustrations by Louise Saunders |
Types of netting
Netting with a knitted mesh and a maximum mesh size of 40 mm will keep out larger birds, possums and flying-foxes. A smaller mesh size may be needed to keep out 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.
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 can't return to the roost within a day.
Suitable netting can be purchased from hardware stores and nurseries.
Frame Method Illustrations by Louise Saunders |
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 teepee frame (see illustration). 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.
You will also need 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 3.5 kg, common ringtails 1.1 kg, and grey-headed flying-foxes up to 1 kg, 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.
Entangled animals
Animals entangled in netting are likely to be injured and highly stressed, meaning any attempt to remove them potentially dangerous for the animal and the rescuer.
If you find an entangled animal, cover it with a towel then contact your local wildlife care organisation or the RSPCA Qld. They will put you in contact with a licensed wildlife rescuer who is trained to handle and care for wildlife.
Do not try to remove entangled flying-foxes. These animals can carry and transmit viruses. If the flying-fox is sick and shows signs of paralysis, or has come into contact with a dog or a cat, contact Biosecurity Queensland as they may wish to inspect the bat. If the flying-fox is dead, use a shovel and/or tongs to remove it and then burn or bury it. Do not touch the bat without wearing gloves. If burying it, ensure that the hole is deep enough so that a dog could not dig it up.
- Importance of flying-foxes
- Living near flying-foxes
- Netting backyard fruit trees
- Flying-fox roost locations
- Authorised flying-fox roost management
- Indicative local government scale maps of urban flying-fox management areas
- Generate an urban flying-fox management area map
- Damage mitigation permits for crop protection
- Flying-fox viruses
- Questions and answers