I've got two 6 foot by 3 foot beds I plan on growing bush beans in. The varieties I'm growing are European Soldier & Kenearly Yellow Eye and the seed spacing that is on the packets says about 2 inches apart, 1 inch deep, and in rows 20-36 inches apart. Since I'm going to be growing these in a 6 foot x 3 foot block instead of a row what would be a good spacing for them?
In my experience the issue of spacing in a block planting comes down to (in this order):
- How much the plant needs for space
- Ease of weeding
- Ease of harvesting
For bush beans, the 20" row spacing is basically the narrowest path from which you'll want to be harvesting. You could maybe get away with planting them 4" apart in a block planting and meet the plant's needs, but a spacing that tight is really hard to weed around, and a 3' wide block of beans at 4" apart will be hard to harvest. If you know you're in an area where you're expecting a lot of moisture while the beans are maturing, you might want to space them further apart so that they can have better airflow and a chance to dry out so they don't get a fungus.
A quick peek at "How to Grow More Vegetables" (John Jeavons) says 6" for bush beans. That's the tightest I'd use; 8" would be easier. I find that 6" is the narrowest space that I can get a hoe through, and then I have to be slow and careful. At 8" I can go faster through a bed.
Both of the varieties you mentioned are for dry beans, so I presume you won't be picking much for green beans. This is something to consider when thinking about harvesting: since you'll wait until the beans are fully mature and mostly dry, you can pull out the whole plant when you harvest, so a tighter spacing will be ok. If you are planning to pick some immature for green/snap beans, then keep in mind that it will be a little harder to harvest from the center of a dense block of plants.
Bottom line: plant your beans at 8" apart in all directions for your 6x3' block.