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.
Step 2: Make a Trellis
Find a type of wood that you have readily available. I used the stems that hold up palm fronds. If you have the right type of palm tree, these grow to about 5 or 6 feet and get really strong once dry. Cut them off the tree and remove the fronds, leaving the straight wooden sticks.
Take two cut branches and form a triangular shape with them. Nail/screw the two branches to one another, and repeat with two more branches (try to keep the two triangular shapes at the same angle. Go outside in your garden, and bury the two loose ends of each assembled unit at least six inches into the ground. Finally, take a fifth branch and attach it to the top of the two triangular end pieces.
Next, wrap a horizontal length of string around the perimeter of the bottom of the trellis. Wrap the string around a few times and tie it off at each branch to make it nice and taught. Use more string to tie vertical sections from the bottom horizontal string to the horizontal wood at the top of the trellis. Repeat this until the whole trellis is has vertical strings every few inches.
If you have a chain link fence, this whole trellis can be skipped. Plant your seeds along the fence and the beans will climb the fence with no problem. If you have a wooden fence, add nails/screws every so often and attach strings to these, and your beans will find them.
Step 3: Prepare the Ground
Step 4: Plant the Seeds
Step 5: Fertilize
So needless to say, fertilizing with manure definitely helps. I've never tried a store bought fertilizer with beans, but I'm sure Google can help. If you have a small pet rodent such as a rabbit though, you get a almost unlimited free supply of little round pellets of bean fertilizer.