Bean Seeds - Pole - Blue Lake Pole FM1K (treated)50 70 days. Annual. Blue Lake Pole vines can grow up to 12 feet long, requiring some kind of growing guidance, such as poles or strings. The oval pods produced are crisp and tender, growing up to 6 inches long. Green beans, also known as string beans or snap peas, are one of the most common vegetables grown. This is due to their simplicity and the fast manner in which they mature; a green bean can be harvested as soon as just fifty days after being