Different pea species have different rates of maturation. Early pea varieties such as Spring and Daybreak can be ready for harvest in 54 days. Sugar pea species, such Snowbird and Snowflake, can take as long as 72 days to ripen. The latter need more time in the sun to photosynthesise, which makes them sweeter. Peas in general all share similar pea-plant stages. They all germinate, flower, fruit and then produce seeds for the next generation.
Pea plants start out as a dry seed. As that seed absorbs water, the outer covering softens and a tiny root called a radicle emerges to gather nutrients from the soil. At the same time, the sprout starts to rise toward the surface. Once the tiny plant breaks through the soil, it unfolds, and two tiny leaves start to grow. The plant continues to grow leaves and the stem starts to lengthen. One stem grows into two, then three and so on, until there is a fully grown pea plant.
At this point the flowers buds start to form and then separate from the leaves.The first petals, usually white or lavender, can be seen before the bud is fully open. Not all of the flowers on a pea plant will open at once. Usually about 10 per cent will open at first and then the flowering gradually increases until the pea plant is covered in blossoms. As the flowers emerge, they attract bees, birds and other insects to pollinate them.
(ref 2, Peas page 138-139)
As soon as a flower is pollinated, the petals drop away and the peas start to form. Just as the blooming of the flowers is staggered, so is the fruiting of the pea pods. This means that fresh peas will be available to harvest for a longer period. Once the pods have reached full size and, if pressed, emit a liquid, they are ready for harvesting. Peas destined to be dried stay on the vine until the pods are brittle and brown and the seeds are hard and dry. By this time the pea plants have reached the end of their life cycle and are dry as well.