With pole beans I space about 6 inches apart, but plant 3 inches then thin. I grow mine off of parachute cord strung on a wire held by conduit poles. Beans seem super easy to germinate. I have no desire to start early. Getting a crop a couple weeks early doesn't matter to me, I'm so busy with other crops, and by June harvesting starts and doesn't end till November. I actually do not like germinating indoors, messy, dirt everywhere, spilled water etc. No thanks. I've been germinating seeds indoors since February, I'm done with it!
I used 3/4 inch conduit, but they really didn't hold, so I'm replacing with 1/2 inch and cementing poles in. I have 600 pound of cement left over from a chimney job, the company just left the cement! OK, I found a use for some anyway!
Here it is, as you can see, the poles were not really strong enough. 1/2 inch should work well.
