Our arbor is being constructed with pressure treated wood. 4 2x2" for the legs, one 1x4" to make the top portion, and a 4x8' trellis plus a 2x8' trellis to fill in and give our vines something to grab ahold of. To attach it to the ground, I decided to use metal rebar. We purchased all of this material from our local big box store for less than $60.
Tolls that I used include the following, but can vary depending on your methods:
drill with 3/8 paddle bit
Now is the time to lay out your materials and start cutting them to size.
Step 1: Assembly
Then I added the trellis to the top of the box cutting it to fit and stapling it in place.
Next I turned the box on one side and attached the legs into each corner using glue and staples, rotating the box as necessary to fasten each leg.
Then for stability, I used the offcuts from the legs to install corner bracing to prevent leaning.
Then it was time to put the trellis on each side. I utilized a clamp to hold the trellis in place while I stapled it onto each leg.
Step 2: Finishing Up
To anchor it to the ground, I drilled a 3/8" hole into the bottom of each leg. Then I hammered a 2' piece of 3/8" rebar into each leg.
My wife already had vines growing where she wanted to place this arbor. Vines are an option but not necessary. We were able to place the arbor where we wanted it then hammer the top of the arbor to get the rebar solid in the ground. Then I used a level to insure the arbor was plumb and level.
So now you can just sit back and enjoy your handiwork and a happy wife.