Apply a 3-inch layer of compost to a well-draining garden bed that receives full sun. Till the compost into the top 6 inches of the soil to provide further drainage and some nutrients.
Sow the bean seeds 1 to 1 ½ inches deep in rows. Space pole green bean varieties 4 to 6 inches apart and space the rows 30 inches apart. Space bush green beans 2 to 3 inches apart and space the rows 18 inches apart.
Water the beans two to three days after planting. Moisten the soil to a 6-inch depth but do not water so much that the soil becomes soggy. Green bean seeds crack and fail to germinate in overly wet conditions.
Water regularly once seedlings emerge, usually within a week of planting. Water once weekly, moistening the soil to a 6-inch depth.
Mulch around the bean plants once they are 6 inches tall. Mulch preserves soil moisture and prevents weed growth in the green bed.
Fertilize green beans once they begin flowering. Apply 3 tbsp. of 10-10-10 analysis fertilizer to each 10-foot row of plants. Work the fertilizer into the soil between the plants so that it doesn't burn the roots.