
I wanted to put in a veggie garden with an arbour for vines, so that winter I started designing one in my laptop using Bryce 3D (closest thing to a CAD program I had.) An architect friend suggested using white PVC pipe as a structural element, which I supplemented with light 1" x 2" wood to be painted white. The wood elements I attached to the PVC parts using zip ties, and I anchored the whole structure to the existing cedar fence with the same ties. Total cost was under $300, including galvanized bolts to fasten the wood parts together. (Always buy galvanized at a marine hardware store for things that will be outdoors in a coastal climate.)

I accomodated an existing young maple tree I wanted to leave for the next generation:
Here is the way I used the PVC pipe parts and related the wood structure to the PVC section:

I did some animated renders of the garden structures:
(iPod formatted movie)
(Windows Media Format)
So I had a clear idea what it would look like even before I went to buy the materials.
Here's what it looked like in situ about 15 months after I built it and planted everything (including a wildflower garden outside the veggie garden):