down in SE PA, the conventional last day to plant beans is July 4th, but you probably get frost before us. If you have room, I'd plant as much as you like right now.

I'm in zone 5 and plant bush beans every 2-3 weeks from late April until mid July (although this last batch may not make it before frost). The first batch is pre-sprouted indoors on a heating mat if the soil is still cold.
I try not to plant too much at each sowing, about 18 plants each time is plenty for my family of four.

Potter, what kind of bush beans are you planting? I thought the general consensus was around 15 plants per person for a few meals a week. I planted 30 for 2 people, thinking that we'd have just enough, although even if it ends up being "too much", I'd greatly prefer that to having too little.

I have squeezed in bush beans as late as late August because the last couple years the killing frost has held off until the first days of November, especially if I cared to throw a row cover over them a couple times on 'iffy' nights. Those harvested in the cool falls were just gourmet quality. Look at your first killing frost date...subtract days to maturity and it should give you the last 'safe' plant date.

When the first planting starts to bloom, I plant another row, and another row when that one starts to bloom. The first planting generally lasts until the second starts to bear, and so on. Last planting here somewhere around mid August.

Steve

I plant Tenderpod, Roma II, Early Bush Italian, and this year I'm trying Valentino. Usually I plant two varieties at each sowing (9 plants each). I do also have yellow wax beans, maybe half as many as the green beans.

Maybe my soil is really good, or my family doesn't eat as many beans as others. We only have beans about 2 or three times a week, there are so many other veggies to eat too :-) So I find 18 plants every 2-3 weeks is enough beans for us.

I find that July 25th is the latest here for green beans.