These giant beans originated in China and can often be found for sale in the produce department of Asian Supermarkets. I got started with growing these giant beans when I bought up a whole bunch of seed packets filled with Asparagus beans in the gift shop of a Ripley's Believe it or Not museum on clearance for 5 cents each. I had much success growing these large beans, and eventually expanded to other variates of giant beans, and have been growing them ever since.
In this Instructable, I will show you the basics of how I grow my beans.
Step 1: Obtain the seeds...
I personally have never purchased from them, but it seems Kitazawa Seed has a good selection of giant beans.
The seeds I used were from the clearance of a Ripley's Believe it or Not museum gift shop (5 cents per packet) and also from Territorial Seed Company. Chances are you won't find these beans in the seed department of your local Home Depot, so the internet is probably your best bet for buying seeds.