Pinto beans are the mature, dried seeds of the plant Phaseolus vulgaris. It is possible to grow pinto beans using dried beans purchased from a grocery store because they retain their reproductive capability, provided they have not been cooked or processed. Success depends primarily on the viability of the specific batch of beans and providing the correct environmental conditions for germination and growth.
Identifying Viable Beans
The most significant hurdle in planting store-bought beans is confirming the seed’s viability, as dried grocery beans are intended for food, not propagation. Beans that have been heat-treated, irradiated, or stored for too long will not germinate. Always select whole, plump beans that show no signs of cracking, damage, or polishing, which could indicate a compromised seed coat or chemical treatment.
A simple pre-planting test can reveal the germination potential of a batch before committing them to the soil. The paper towel method involves moistening a towel, placing a handful of beans inside, rolling it up, and keeping it in a sealed bag or container at room temperature. Viable beans should swell and begin to sprout a small root, or radicle, within three to five days. If less than 60% of the tested beans sprout, the batch may not be worth planting due to low germination rates.
Preparing and Planting the Beans
Once viability is confirmed, an optional overnight soak in water can speed up the germination process by softening the tough seed coat and initiating water absorption. Direct sowing is the preferred method for all beans because they are sensitive to having their roots disturbed, which makes transplanting seedlings difficult. Plant the seeds after the last spring frost, when the soil temperature has consistently warmed to at least 60°F, as cold, damp soil significantly increases the risk of the seeds rotting.
Pinto beans thrive in full sun, requiring six to eight hours of direct light daily, and prefer a well-draining soil with a pH range between 6.0 and 7.0. Plant the beans approximately 1 to 1.5 inches deep, spacing them four to six inches apart within the row. Rows should be spaced at least two feet apart to allow for proper air circulation and ease of harvesting.
Monitoring Growth and Maturation
After planting, consistent moisture is necessary until the seeds germinate, which typically occurs within eight to fourteen days. Once the seedlings are established, the plants require about one inch of water per week. Deep, infrequent watering is preferable to shallow, daily misting. Water should be directed at the base of the plant to keep the foliage dry, which minimizes the risk of fungal diseases.
Pinto beans come in both bush and pole varieties. Commercial dried beans are most often the bush type, which grows to about two feet tall without support. Pole varieties will need a trellis or fence installed before planting to support their vining growth. Common pests include the bean leaf beetle and black bean aphid, which can transmit mosaic viruses and require proactive scouting to manage.
The total time from planting to harvest for dry pinto beans generally requires 90 to 150 days. For dry beans, the pods must be allowed to dry completely on the plant until they turn a yellow-tan color and the seeds rattle inside. This late-season drying is necessary to cure the beans for long-term storage.