Navy bean seeds are planted in a vegetable garden area as a dry bean. The beans grow as a vine plant and are harvested at maturity 70 to 120 days after planting. Navy bean pods grow up to 12 inches long and are mature once they become dry and the leaves fall off the plant. The bean plants must be evenly watered throughout the growing season to prevent a decrease in pod growth from plant stress.
Prepare a garden area that has full sun conditions and a fertile, well-draining soil. The navy bean planting location should be rotated each year to prevent disease problems.
Apply a 5-10-10 fertilizer to the soil before planting. Work the fertilizer into the soil with a tiller to 6 inches deep. Do not apply a high-nitrogen fertilizer as this will decrease pod growth.
Plant the navy bean seeds once the danger of frost has passed in the spring. The soil should be at a temperature of 50 degrees Fahrenheit to prevent a decreased germination rate. Form planting mounds approximately 40 inches apart.
Plant five to six seeds in each mound at a depth of 1 inch. Space the rows 3 feet apart to provide room for support poles. Thin the seedlings to three to four plants in each mound once they are several inches tall. Cut the weaker seedlings with scissors at ground level to prevent a disruption of other seedlings.
Form a tripod around each planting mound by placing three to four poles into the ground and tying them together at the top with twine. The poles should be 6 to 7 feet tall.
Train the vines to grow up the tripod poles as they form. Gently wrap the vines around each pole so the runners grab hold and continue to grow upward.
Clip terminal vine growth once it reaches the top of the tripod. This will stimulate the vine to branch.
Apply an ammonium nitrate fertilizer rated at 33-0-0 as a side dressing once the navy bean plants have flowered and the pods are set on the plant. Work the fertilizer along the row area next to the plants and lightly water to increase absorption.
Apply 1 inch of water to the navy bean plants each week to prevent the plants from drying out. Water the plants in the early morning to prevent them from remaining wet overnight. This will lower the chance of disease.
Apply mulch around the bean plants to prevent weed growth. Lay black plastic sheeting or spread an organic mulch of weathered straw or grass clippings around the plants and between the rows.