Last year I ordered some runner beans (Golden Sunshine and Painted Lady) from a mail order catalog. They grew great!! This fall I saved seeds from both but my saved seed looks different than the company seeds. For one thing, my seeds are at least twice as large as the packaged lot....and although the markings on the seeds are the same, the color is not.

I thought that hybridization may account for the difference, but to my knowledge, runner beans don't cross pollinate readily, and aren't hybridized either. I may be completely wrong about this.

Do you know why my saved seeds are so different from the parent plant seeds?