Bean plants, classified as angiosperms because they flower, grow from a seed formed inside the bean pod. Bean seeds are called "dicots" due to the development of two cotyledons, or seed leaves. The cotyledons supply food to the plant. The seed has other parts: an embryo and seed coat. The embryo contains the root, stem and leaves. The seed coat protects the inner parts of the seed. Bean seeds maintain viability for 3 years. The embryo within the seed waits in a dormant state for conditions to trigger germination.
Bean seeds require warmth, air and water for germination. Soil temperature needs to be above 60 degrees F. The seeds have the best chance for growth in well-drained, loose and moist soil. The seed absorbs moisture causing an increase in pressure. The seed coat ruptures and hormones direct the growth of the plant. Bean seeds take up to 2 weeks to germinate in ideal conditions.
The radicle, which develops into the plant root, emerges from the embryo. The root grows down into the soil and branches out into lateral roots. The stem grows and the cotyledons open. The emerging bean plant continues to need warmth, moisture and air, but it now also needs light. The plant grows toward the light and develops true leaves. Bean plants grow rapidly with the proper environment. Maturation depends on the variety, but most mature in 45 to 100 days.
Beans, a member of the legume family, come in different groups: shell and snap. You can eat snap beans fresh and shell beans, such as black turtle, fresh or dried. Beans have different growth behavior. Bush beans grow up to about 3 feet tall and do not need support. They germinate quickly, usually within 1 week. Varieties of bush beans include adzuki, garbanzo, mung and kidney. Pole and runner beans, such as scarlet emperor and wax beans, require trellising and reach heights of 12 feet easily. Germination takes approximately 2 weeks for pole and runner beans.
Picking beans frequently encourages increased production. Pick daily for beans you plan to eat fresh. Snap beans have the best flavor and texture if picked while tender and the seeds within the pods remain undeveloped. Shell beans need to mature fully on the bush or vine. Harvest when they turn brown and dry. You can cut the whole plant and dry them indoors during very wet weather. The dried beans keep for a year when stored in a dry, airtight container.