Protein-packed, fiber-rich pinto beans grow as easily in the home garden as they do in commercial fields, provided you have enough frost-free days to see them through from planted seed to the dried-pod stage. Although the beans taste fine when eaten in the fresh stage, most people grow them as shell, or dried, beans. The speckled beans look lovely stored in glass jars, and cook to a light pink color and meaty texture. They work well in rice dishes, in soups and in Mexican recipes.
Choosing Pinto Bean Seeds
Decide which type of pinto bean plant works best for your garden--bush beans, pole beans or "half high" beans, also known as "half-runners." Bush varieties produce more quickly, but pole beans allow for a greater number of vines to be planted in the same amount of space. Half-highs yield more than bush beans, and support each other as they grow, eliminating the need for trellises. Because pinto beans require at least 90 frost-free days in the garden, northern gardeners should pay extra attention to the growing time noted on the seed packet. Those living in Zone 4 or colder may not be able to grow pinto beans.
Many nurseries either sell dried bean seed which are dusted with fungicide or offer fungicide blends, which the home gardener can use to treat their own seeds. The treatments usually also help beans fix nitrogen in their roots, lessening the need for fertilizer. Check with your extension service to determine which diseases affect dried beans in your area and whether it recommends treating pinto bean seeds in your region. Pintos grown in high-humidity areas suffer more from bacterial disease and fungi than those in arid climates. If you choose not to use fungicide, make sure the soil is at least 50 degrees, with no more frost dates forecast, before you plant the pinto beans.
Give your pinto bean crop its best start by making sure the ground doesn't slope steeply or puddle during the rainy season. It's also important to establish pinto beans where beans or other legumes haven't grown recently, and where they will receive at least six hours of sun each day.
Pinto bean growth suffers from iron deficiencies in alkaline (high pH level) soil. Have your soil analyzed by your local extension service and choose a garden bed containing neutral to slightly acid soil, if possible. To lower pH levels, dig in the amount of acidic material recommended by the extension service, such as peat moss, sawdust or calcium sulfate. Beans need less in the way of fertilizers than other vegetables. If using a synthetic fertilizer, choose 5-10-10, which has less nitrogen; beans fix nitrogen in the soil and therefore don't need heavy applications of it. The beans will appreciate at least one additional application of fertilizer during the growing season.
Planting and Growing
If your soil is on the clay side, plant seeds one inch deep to discourage seed rot. Cover the seed with sand or compost rather than the heavy clay soil. In sandier soils, put the seeds about 1.5 inches deep. For bush-type beans, plant 2 to 4 inches apart, with rows 2 or 3 feet apart. If planting pole beans up a trellis or tepee pole, establish each seed six to 10 inches apart, poles 3 feet apart, with about three seeds per pole. Once the seedlings emerge, mulch them with a few inches of organic material, if desired. (Pine needles, which are acidic, work well in alkaline soils.) Otherwise, keep the area well-weeded. Do not overwater the beans. Pinto beans tolerate drought conditions better than most shell beans, so it's better to air on the side of slightly dry soil rather than boggy, disease-promoting soils.
Dried beans store best when their moisture content reaches 18 percent or less. Home gardeners won't be able to measure moisture content that precisely, of course, but certain "all clear" signs exist. When most of the pods are yellow and a few are brown, and are dry to the touch, it's harvest time. Another clue lies in the beans themselves. Bite down on a few. If you can barely leave a dent, the beans are harvestable. Shell the pinto beans and store them in glass jar or other moisture-free environments.