Stages of Pinto Bean Plant Development

Seeds

• The seed of the pinto bean plant is the bean itself. It is a pink or buff color with reddish-brown blotches. The seed coat is very hard; therefore, soaking the seeds in warm water for 24 hours before planting improves germination time. Pinto bean plants can be successfully grown from the pinto beans from the grocery store. However, the unknown variety may not be compatible with your climate. Choose certified seeds from a reputable nursery in varieties that grow well in your area. Most certified pinto bean seeds have been treated with a fungicide to prevent diseases in the early stages of growth.

Plant Types

• Pinto beans varieties fall into four different types: bush, indeterminate trailing vine, indeterminate upright vine and upright short vine. Most varieties of pinto beans are indeterminate trailing vines that grow very long and need support. Agassiz is a compact bush variety and RS-101 is an upright short vine variety. Aztec, Remington and Winchester are indeterminate upright vines with strong climbing tendencies.

First Stages of Growth

• At about 10 to 14 days after planting, the first leaves emerge and completely unfold. Within another two weeks, three leaf nodes develop and secondary branching begins. At this point, a new node develops about every three days and flowers begin to bud and cluster but not yet open.

Blossoms

• After about 40 days from germination, vining pinto bean flowers will begin opening. Bush-type pinto beans blossom at about 50 days from germination. Pods develop from the blossom in just a few days.

Pods and Seeds

• About a week after the pods first appear, they are 3 to 4 inches long, but seeds are not visible yet. During the next week, pods reach over 4 inches long and the seeds become discernible in the pods.

Maturity

• During the final 30 to 40 days of growth, the seeds mature from green seeds to fully ripe beans. During this final stage, the leaves begin yellowing and blossoms and new pods stop developing. By final maturity, the pods have turned yellow, only about 30 percent of the leaves are still green and at least 80 percent of the beans are ripe and ready for harvesting.