Hello Ashita. That is very large for a fresh shelly bean and huge for dry seeds.

How long does it take to produce a crop of these? When do you expect your first frost? - Dick

They are dry seeds, Dick! And I have no idea how long it takes! I bought these in a grocery store. These ones are grown in Japan, but I also found them on a Japanese website, but from China. According to the packet they are grown in the cooler areas of the country.

I am in central Tokyo and we don't really have much frost! December is still quite warm.Outside the city they do, in January I think.

I am hoping to get a crop of beans this year (my garden is very small, and perhaps crop is wishful thinking). I planted too late this spring, and the weather got too hot, and I only got about two servings of green beans. I don't really mind what variety I grow!

Ashita

I would assume 120 days to dry seed and would try planting them 4 months before possible frost. - Dick

Runner beans are from the highlands of Mexico. They are adapted to a cool long season temperate climate. They don't do well above about 85 degrees. In my experience, the larger the beans, the longer they take to mature. I would suggest 5 months (150 days) as a safe number for planning on a crop.

150 days makes sense. So if you planted them soon they would be blossoming in cooler weather.