The Purple Pole Bean is a vigorous climber that produces pods that are deep purple on the outside with a bright green interior and white seeds. The pods turn green and are tender and flavorful when cooked. Plant when the soil temperature is above 60 degrees and up until 3 months before the first frost. Grow pole beans on trellis poles or on a mesh fence so they can climb. Harvest when pods are 7-8 inches long to encourage new pod growth.