Pinto beans (Phaseolus vulgaris) are herbaceous annual plants that grow during the warm summer months. The beans are both high in protein and inexpensive to produce and buy, making them an important food crop. Pinto beans are just one variety in the species Phaseolus vulgaris. Other beans under the same scientific name include black beans, northern beans, kidney beans, navy beans and white beans.
Annual plants complete their growing cycle in a single season. The growing cycle extends from seed germination, through stalk and leaf growth, flowering and seed production to death of the plant. Pinto beans are annuals that complete the growing cycle between the last spring frost and the first winter freeze.
Beans, including pinto beans, germinate when the soil temperature is at least 50 degrees Fahrenheit. In areas with a short growing season, it is important to get bean seeds in the ground as soon as the soil warms sufficiently. In areas with a longer growing season, pinto beans can be planted during spring and early summer. Pinto beans require 90 frost-free days between 50 and 85 degrees Fahrenheit to complete the growth cycle and produce for harvest.
Once pinto beans produce mature seed pods and seeds, the plant and roots die. Most seeds are programmed to go dormant during the cold winter season and then germinate when the soil warms up in spring. That's why pinto beans do not germinate in soil that is colder than 50 degrees Fahrenheit. If the new shoots emerged during winter, the seedlings would be killed off. Harvest pinto beans when the bean pods dry and turn brown. Store extra seeds for spring planting in a cool dry place.
Extending the Growing Season
Gardeners can extend the growing season by starting beans indoors three to six weeks before planting out in the garden. In hot climates where summer temperatures regularly rise above 85 degrees Fahrenheit, beans must complete their 90-day growth cycle before things turn hot, or they will not produce pods successfully. In cold climates, the beans have to complete the cycle before the first frost. Beans do not transplant well, so start them in a peat pot. When it's time to transplant the seedlings, plant the whole pot. It will rot away, leaving the roots free to grow into the soil.
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