Is Peat Moss Good for Beans or Peas?

Peas And Beans

• Peas and beans are legumes, plants in the pea family with irregularly shaped flowers, and both have symbiotic relationships with bacteria that form nodules on the roots. These bacteria provide nitrogen to the plants, eliminating the need for high-nitrogen fertilizer. Peas grow best in cool weather, and need a soil with a pH between 6.0 and 6.7 Beans need a slightly more acid environment, pH 5.8 to 6.3. Both need a moist but well-drained soil and adding extra organic matter such as peat moss is helpful in improving the water-holding capacity of the ground.

Understanding Peat Moss

• Peat moss is the partially decayed remains of the sphagnum moss that has accumulated in very acid bogs over many years. It is acidic, poor in nutrients, hard to wet once it dries out and excellent at retaining moisture. Peat can also be expensive, but persists well in the soil. Because it resists compaction, it is especially good at opening up heavy clay soils. Because of peat's acidity, with a pH of about 4.0, test your soil and add ground dolomite limestone with the peat moss if needed.

Adjusting the pH

• Ground dolomite limestone is a type of rock high in calcium and magnesium and has the advantage of adding these essential nutrients to the soil as well as raising the pH. Four to five pounds per 100 square feet is an average amount to add if your soil is naturally acid. If adding peat moss, put on an extra pound or two, especially if you are growing beans.

Add Peat Moss

• Thoroughly moisten a bale of peat before digging it into the soil. Because dry peat repels water, you may need to add a bit of dish soap to the water as a surfactant, a wetting agent. Hot water from a hose that has been sitting in the sun will also be absorbed more quickly. Spread a 1- to 2-inch layer of peat over the top of the soil, add lime if needed and a sprinkling of all-purpose vegetable fertilizer, then use a shovel or garden fork to mix it into the top 6 to 8 inches of soil.