DIY - Trellis for peas & beans

At the rate the peas are coming up I figured I had better get a trellis of some sort ready. Because the soil is so lightweight I didn't want to just shove sticks into the containers and run string back and forth. I'll make my trellis out of slender bamboo poles that I picked up on clearance. Bamboo looks great in a garden or greenhouse, so this should work well. I can also custom make the trellis to fit my self watering containers.
 
My first attemp was a traingle or 'A' frame design. This would work great for one or two rows of peas, however I have 4 rows of peas in my SWC's. I'm afraid that the 'A' frame trellis will not have enough room at the top for all of the plants. The nice thing about building with string and bamboo is that it's east to re-arrange things without throwing stuff away. For the instructions, I will pretend like I never made any mistakes and do a simple step-by-step of what I  did to built this.
 
The construction method I used is simple: tie string around two pieces of bamboo in a criss-cross patters and knot tightly using a cotton twine.
 
Step 1
Start at the base. This will ensure that the trellis fits the container that you are building for. Build a square or rectangle to the size you need so that it sits on top of your container rim. From each corner of the base attach vertical poles as tall as your crop requires.
 
Step 2
The top is pretty much identical to the base - a square or rectangle of bamboo. The top should be attached to the vertical poles. At this poin the entire structure might not seem very sturdy. This will be addressed in step 3.
 
Step 3
At this point you should have a frame in the shape of your trellis. Now we need to add something for the plant to climb. If the trellis is more than four feet tall, it might be a god idea to add a cross-beam (similar to the base and top) at a mid-point. Using the string, connect a few corners to strengthen the trellis frame. Also add horrizontal strings every 10 inches or so from the bottom up for the plants to climb.
 
That completes your trellis. I did not go into detail on the siz or spacing or anything becuase you will have to do that on your own depending on your container and crop. For cheap bamboo, look for clearance sales at the big stores. The ones I bought were pre-assembles in bundles that must have been intended for some sort of decorative purpose.  I easily took them apart and had 40 or so nice straight 1/4" diamter bamboo poles.