Green beans are immature bean pods. The pods are eaten as a vegetable. If left to mature, the pod becomes fibrous and the seeds inside the pod develop. Once the pod is mature and dry the seeds inside can be saved for eating as a dry bean or for planting. Bean plants are heat tolerant plants, especially the yard long beans. Beans are classified as either bush or pole bean. Bush beans can be grown without any support or trellis. Pole beans are vining plants and need a trellis to grow properly. Green beans are very productive and only a small planting is needed to get large harvests!