How Does Sand, Clay or Potting Soil Affect the Way a Bean Grows?

There are many varieties of bean plants that grow in bushes or vines. Most bean plants need full sun and well-drained soil to grow properly. Potting soil is usually the best medium to plant beans in since it contains a mixture of soils and added fertilizers. If a bean plant is planted in sandy soils, it will require more frequent watering and fertilizing. Clay soils are dense and hold water. Some varieties are more tolerant to clay soils than others, but watering should be less frequent than with potting or sandy soil.

Sandy Soil

Sandy soil is not ideal for growing plants; while the soil drains quickly, important nutrients are washed away in the process. This process is called leaching and does not allow plant roots to properly absorb all the nutrients. Without intervention, planting beans in sandy soil can cause the bean plant to die or result in severely stunted growth. It may not even produce any edible beans because of the lack of nutrients.

Clay Soil

Clay soils are more dense than sandy soils and hold water very well. Water drains slowly in clay soils, causing puddles. Plants sitting in puddles for too long can cause mold, rot and other diseases. If the roots become waterlogged and rot, the plant will eventually die if it is not allowed to dry out between watering. Not all varieties of beans can adapt to clay soils, but some, such as purple pole beans, can grow very well in dense clay soils with little intervention.

Potting Soil

Potting soil is the preferred type of soil for planting beans. The makeup of potting soils can vary, but they usually contain added compost, manure and various types of soil to improve drainage. The added nutrients provide ideal soil conditions and help the bean plant establish strong roots, healthy foliage and ideal beans for eating.

Solutions to Sandy Soil

When growing beans in sandy soil, it is important to regularly check the soil to make sure it is moist because the water drains quickly. Beans planted in sandy soil must be watered more often. The natural leaching process will also require the use of organic material like manure or compost to restore nutrients. A raised garden bed with fresh potting soil or organic compost placed over the sandy soil can also be used to properly grow beans.

Solutions to Clay Soil

Clay soil can become more adapted to growing beans by adding a mixture of compost or well-rotted manure. Mixing the clay soil with compost allows improved drainage and prevents the soil from becoming waterlogged. Adding mulch should be avoided since the mulch will cause the soil to hold moisture even more. A raised garden bed placed above the clay soil can also help when planting beans. The raised garden bed should be about 4 to 6 inches high.