Asparagus

The underground portion of the plant consists of a network of rhizomes, fleshy storage roots, and fibrous roots. The fleshy roots (as well as the spears) are initiated from the rhizomes. Together, the fleshy roots and rhizome make up the crown, which is the perennial portion of the asparagus plant. Fleshy roots serve not only as storage organs for the carbohydrates received from the fern, but also as the site of fibrous root development. Fibrous roots, which live for one or two seasons, function in the absorption of water and nutrients from the soil.

The word asparagus comes from the Greek asparagos, meaning shoot or sprout. Asparagus spears are, in fact, edible shoots that develop on rhizomes when the soil temperature is warm and the water supply is favorable. The spears, if not harvested, develop into ferns 4-6 feet tall. Carbohydrates and other compounds necessary for plant growth and development are produced in the ferns throughout the growing season. These substances are translocated to the fleshy roots, where they are stored and used to produce spears the following spring.

Asparagus plants are dioecious, meaning that male and female flowers are produced on separate plants. The flowers are small, bell shaped, and whitish green. Male flowers are more conspicuous than female flowers. Following pollination of female flowers by bees, a berry, which has one to eight seeds and turns red at maturity, develops. The seeds, which are threshed from the berry when dry, are single, large, black, and generally round with one flattened side. Female plants are somewhat less productive and shorter lived than male plants because of the energy allocated to seed production. Thus, in a given planting of dioecious hybrids or plants from open-pollinated sources, the ratio of male to female plants initially is 50:50. As the age of a planting increases, the ratio of male to female plants increases.