What Affects a Pinto Bean Plant's Growth?

Climate

• Pinto beans are a warm-season crop and grow well in areas with a warm climate, but they do not tolerate extreme heat as well as other dry beans. They can be grown in cooler areas as well but should be planted only after all danger of frost has passed and soil temperatures are at least 60 degrees. Frost can cause severe damage from which pinto bean plants may never recover. Frost dates are available from your state's university extension service.

Soil

• Pinto beans grow best in fertile, sandy loam with an acidic or neutral pH. Alkaline soils can cause poor growth due to iron deficiency. Nitrogen and phosphorous are important nutrients for growth, but excessive nitrogen can cause problems. Pinto beans also grow poorly in clay soil. You can have your soil tested at your nearest university extension office; the results will include pH and nutrient levels along with recommendations for amending your soil.

Water and Sunlight

• Pinto beans need ample water and will probably need irrigation if you live in a dry climate. The soil should be kept uniformly moist but should never be watered to the point of saturation. Wet, waterlogged soil can prevent pinto bean plants from absorbing oxygen through their roots. Ample sunlight is important as well: Pinto bean plants grow poorly and produce a diminished yield on shady sites.

Diseases and Pests

• Pinto bean plants are susceptible to a variety of diseases and pests that may limit growth and yield. Bacterial blight, bean rust, fusarium root rot and nematode are among the more common diseases, and potential insect pests include aphids, spider mites, beet army worm and cutworm. Treatments are available for each of these problems, but the chances of problems can be lessened by keeping your garden free of weeds and debris and by rotating crops. Crop rotation also helps pinto beans by maintaining soil nutrient levels.