Germination

• The bean is a dicot, which means that it has two cotyledons--tiny, leaf-like structures that store nutrients within the seed. The seed coat becomes soft when it absorbs moisture, allowing the seed's two halves to split and the main root to extend. Bean seeds can be germinated in any warm, damp place, ideally in soil, but folding them into a paper towel dampened with warm water also works.
  
  

Roots and Sprouting

• The first shoot that extends from the bean seed is a small, curved stem called the hypocotyl. As soon as the hypocotyl reaches sunlight, phototropism causes it to straighten and grow upward. The seed coat dries up and peels off and the two cotyledons unfold. The bean plant extends its taproot, a root system that consists of smaller secondary roots shooting off from one large primary root. As the plant matures, the primary root grows down deep in search of moisture.
  
  

Leaf Growth

• Once the cotyledons unfold, photosynthesis, during which the leaves take in sunlight, and transpiration, during which the roots absorbs water, work together to provide the plant with nutrients. The initial cotyledons will dry up and give rise to foliate leaves, single leaves that grow from the stem, and trifoliate leaves, shoots that contain three leaflets. When a bean plant establishes sufficient leaf growth, usually when about eight or nine shoots become visible, it enters the reproductive stage.
  
  

Flower and Fruit

• Bean plant flowers are categorized as "perfect" flowers because they contain both stamens, male organs, and pistils, female organs, which are both necessary for reproduction. When a plant is pollinated, the ovaries of the flower grow into a seed pod, and the flower then withers and falls off. Bean seeds will harden inside the pods as they ripen. The length of time it takes the beans to fully ripen depends on the variety of the bean.
  
  

The Seed-to-Seed Process

• The lifespan of a bean plant depends on environmental factors, such as weather and fertilization. As an annual, the plant dies every year, though unharvested seed pods that have fallen on the ground may dry up and break open. In what is called the seed-to-seed process, the bean seeds germinate and start the cycle over again. Dead, shriveled plants can be tilled into the ground and nitrogen from rotting plant matter will provide nutrients for the new seedlings.