vegetable patch design
Raised bed building materials
Raised bed building materials - Page 1
While there are a number of different building materials that can used to make raised beds no single product stands out as they all have their advantages and advantages.   Below is a comparison of some materials for you to consider. Unless stated otherwise I have at least tried these materials at some stage.  BLACK text indicates positive points while RED is negative.

Second hand hardwood framing timber
Photo of a raised bed border using second hadn framing timber
Raised bed  bet hardwood framing timber border.
  • Very cheap  
  • Lighter and easier to handle    than railway sleepers

  •  Rots out much quicker than Redgum or treated pine timber.  
  • Two pieces have to be nailed on top of one another to get the right hight, which involves more work
  • Can look pretty unsightly

Galvanised roofing iron

Raised bed made with galvanised roofing iron.
Corrugated roofing iron is also relatively cheap when bought second hand.  It also has the advantage of being quicker to build with and raised beds and can be raised to a higher height then beds made of hardwood framing timber.  All you have to do is cut it to the length you want and bend one edge over to get the desired height and to create a blunt edge, which will become the top of the raised bed wall. The bottom and top edges can be held in place by pop riveting them together.  The other advantage of corrugated iron borders is that the bottom edge is quite sharp and can be driven deep into the ground.  Which is very useful if you have Couch grass nearby.  Couch is shallow rooted and if the iron is pushed far enough into the ground it will stop the Couch getting into the vegetable bed.

The main drawback with galvanised iron is that it will begin to slowly oxidise when in contact with soil, and in doing so it slowly releases zinc into the soil.   Zinc is found naturally in soil but excessive amounts of zinc can cause health problems.  So if you are uncomfortable about zinc leaching into the soil do not use galvanised iron to make your raised beds.

Photo of border bed made out of second hand railway sleepers
Border raised bed made out of
second hand railway sleepers.

Photo of Redgum 200 X 50 landscaping timber
New Redgum 200 X 50 mm landscape gardening sleepers.  The weldmesh on top is to stop blackbirds scratching mulch onto the paths.
Second hand railway sleepers
  • Very long life  
  • Lighter and easier to handle    than railway sleepers

  • Expensive  
  • Very heavy and difficult to     manoeuvre
  • Very thick which takes up a    lot of vegetable bed space  

New Redgum landscape gardening sleepers
  • Very long life  
  • Lighter and easier to handle    than railway sleepers.

  • Expensive  
  • Heaver than treated pine landscaping timber
  • Probably environmentally unsustainable as the timber is being sourced from natural Redgum forests that are currently under serious environmental threat
  • Only available in Australia