An arbor can add a very attractive and functional element to your square foot garden. They are not difficult to build, but you must make sure that you set them properly so they don't steal too much sunlight from the smaller plants in the garden.
Step 1 – Decide on the Materials
There are several convenient materials that can be used to build an arbor. Electrical conduit is cheap and flexible, and even copper or plastic tubing is not too pricey. If you have an idea of the weight of the plants that are likely to be trained up the arbor you will have a good idea of how strong it has to be.
Step 2 – Create the Anchor Points
To be able to stand alone the arbor must have a good support system. A fence post or steel bar driven into the soil next to the garden will provide a good level of upright support. In loose soil they should be driven at least 18 inches into the soil, but 20 to 24 inches would be better. Drive two in at the corners of the garden box and drive two more along the side of the garden box at the first 1 foot grid line. The uprights of the arbor can be tied to the fence post or steel bar by pipe clamps.
Step 3 – Build the Arbor
You will need to make a roof for the arbor that will span the four support posts. If you are using tubing you can make the spans of the roof by bending lengths of tubing to fit across. You can use a manual tube bender to create the 90º bends at each end of the cross pieces so that they will fit to the uprights with a simple collar. You will finish up with two frames a foot apart.
Step 4 – Put in the Plant Support
The frame at the back of the square foot garden should be made ready for the plants. It should be filled with a piece of welded wire net tied to the sides and top of the frame. The two 1 foot sides should also be filled using welded wire net. Even without any plants the arbor will look quite attractive.
Step 5 – Support Heavy Fruit
The arbor will be quite strong and will be capable of supporting heavy fruits, even water melons! If the vines do not seem to be holding up well because of the weight of fruit you'll have to provide extra support for them. This can be achieved effectively by using old tights or stockings to create slings for the fruit. The slings can be hung from the sides and back of the arbor.
Covered with vines, the arbor will become invisible and your garden will take on a vertical appearance. Imagine the impact of a visitor seeing a water melon growing five feet above the ground!