Urban Food Garden

DETERING BIRDS (5)

DETER: BIRDS

This section looks at how you can deter birds from damaging your vegetables.

WIRE MESH

Birds such as Starlings and Blackbirds can wreck havoc in a vegetable patch by scratching up seeds and young seedlings in their search for worms.
The most direct way to prevent this is to lay pieces of wire mesh over any seeds you have just planted. While the wire can be laid straight on the bed the best method is to raise it two or three centimetres above the ground (to give the seeds room to grow). This can be done by making a wooden frame for the wire mesh to sit on.
However, if the gauge thickness of the mesh is heavy enough to support it’s own weight, it is easier to simply bend the edges of the mesh over suit forms it’s own border. Eventually, as the seedlings grow, you will have to remove the mesh. But by then the plants are usually big enough not to be threatened by scratching birds.

While this method offers better protection than the phalanx stick method its main drawback it that as the seedlings get bigger they will grow through the wire.  If you fail to remove the wire in time then you will either damage your vegetables will removing it or will be unable to remove the wire at all, which can cause your vegetables to become stunted as the growing stems are strangled by the mesh.o

Weld mesh wire with the edges turned down to raise the mesh a few centimetres above the soil.

PHALANX STAKES

Another method of protecting seeds and seedlings from scratching birds is to drive 10 to 20 cm long stakes into the ground. They should be driven in at different angles in the fashion of a Greek battle phalanx. While determined birds can still get in among the sticks they are reluctant to do so as the sticks make it difficult for them to fly, which exposes them to predators. 

The big advantage of using stakes over wire mesh is that the stakes do not have to be removed before the vegetables get too big, they even can be used as support for vegetables such as bush peas.

Wooden Phalanx stakes

The simplest way to protect your seeds and seedlings using the Phalanx Stakes method is to make your stakes out of fruit tree prunings.  As you prune your fruit trees in winter simply cut your prunings to the right length and store in preparation for using them when planting in Spring. 

While being very environmentally friendly the disadvantage of using fruit tree prunings as stakes is that they only last two or three years before becoming too brittle, and I found that I could never cut enough to meet all my needs (I use a lot of phalanx stakes).

Wooden stakes made out of tree prunings protecting peas seedlings.

POLYPIPE sTAKES

A more permanent alternative to wooden sticks is to make them out of irrigation polypipe.

Cut lengths of low density 13 mm polyethylene pipe (polypipe) into 20 to 30 cm (4 to 8″) lengths and drive them into the ground as described above. Each cut is best made at a 45 degree angle to make it easier to drive the stakes in.

The big advantage of polypipe stakes is that you can make as many as you need and they last a lifetime, not just two or three years, as is the case for stakes made out of tree prunings. Polypipe stakes are now my preferred method of protection for birds scratching the ground, these days I rarely use wooden stakes or wire mesh.

Polypipe stakes protecting young bush bean plants.

BIRD NETTING

The problem with stakes or wire bird protection is that they only protect your seedlings from scratching birds.  They to little to deter birds that eat leaves, such as sparrows.  The only way to protect leafy green vegetables such as silverbeet and lettuce is to cover them with bird netting.

Damage done to silverbeet leaves by sparrows.

BIRD NETTING HOOP FRAMES

To be effective bird netting needs to be draped over a frame.  An easy way to make a frame is to use standardised lengths of agricultural polypipe to form hoops.  I use two standard polypipe lengths.

1.2 Metre Lengths Of 19 mM Low-density Polypipe

Usually placed over at risk seedlings and removed when the plants get larger. Ideal for immature lettuce plants as sparrows mainly target  lettuces when they are young and tender, they usually leave mature lettuces alone.

I place the hoops in the shape of a cross or at slight angles to each other across the bed I am protecting, driving the ends into the ground to secure the hoops in place. The ends of the hoops are cut at a 45 degree angle to make them easier to drive into the ground.  I use standardised lengths as they are interchangeable and create an even ceiling.

ADVANTAGES SUMMARY

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ADVANTAGES

  • Very quick and easy to set up and dismantle.
  • Cheap to build.
  • Modular, the length can be varied while maintaining a constant height.

DISADVANTAGES SUMMARY

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DISADVANTAGES

  • Only suitable for small or immature vegetables, not suitable for larger vegetables such as silverbeet.

Closeup of 1.2 metre long polypipe hoops supporting netting over young bush bean plants.

2.4 Metre Lengths Of 3/4 High-Density Agricultural Polypipe

 Placed over plants for the entire life cycle of the plant. These larger hoop frames are ideal for vegetables such as silverbeet which, (at least in my garden) need to be protected from sparrows at all times.

To build the frame with these 2.4 metre pipes I place two hoops in the shape of a cross, driving the ends into the ground to secure the frame in place. The top where the hoops cross is tied together for added strength. The ends of the hoops are cut at a 45 degree angle to make them easier to drive them into the ground.  I use standardised lengths as they are interchangeable, making them easy to set up in tandem to make a long row.

As this pipe is stronger the lengths can be longer without the structure collapsing, which means it can cover a larger area to a higher height.  They are also strong enough to support polyethylene plastic, so you can use them to build temporary polytunnels in the winter.

ADVANTAGES SUMMARY

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ADVANTAGES

  • Quick and easy to set up and dismantle.
  • Relatively cheap to build.
  • Modular, the length can be varied while maintaining a constant height.
  • Strong enough to support a plastic covering, so they can double as polytunnels in the winter.

DISADVANTAGES SUMMARY

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DISADVANTAGES

  • The edges are lower than the centre, which means you cannot grow as much in them as you can using a square frame.
  • Lower ceiling than a square frame.

Bird netting over  2.4 metre lengths of 25 mm High-density agricultural polypipe.  The hoops can be set up in tandem to create a long row.

BIRD NETTING SQUARE FRAMES

An alternative hoop frames is a square frame using modular corner brackets.

There are a number of these corner brackets sets on the market but I  used Build A Frame corners to build mine as they are made of steel and therefor should last longer, most other corners brackets on the market are made of plastic.

The main advantage of square frames is that it they are both higher than hoop frames overall and uniformly high across the top.  This means you can grow vegetables closer to the edge and they are easier to access. 
The main disadvantage is that they are more expensive than hoop frames and take longer to set up and pull down.  But they are excellent as permanent or semi-permanent frames.

ADVANTAGES SUMMARY

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ADVANTAGES

  • Have a higher ceiling than hoop frames.
  • Vegetables can be planted closer to the edge than hoop frames.
  • Can be covered with plastic to convert it into a polytunnel in winter.

DISADVANTAGES SUMMARY

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DISADVANTAGES

  • More expensive than hoop frames.
  • Slower to step up and pull down than hoop frames.

Modular square bird netting frame built using Build A Frame corners and 25 mm thick stakes.

Closeup of a Build A Frame corner (top) and a star picket used to weigh down the net.  Star pickets or lengths of wood are ideal for pinning down bird netting as they are easier and quicker to remove than pins.

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