Garden green beans grow either as bushy plants, or climbing plants that need support. The climbing varieties are better known as pole beans. There are several types of common pole beans, including 'Blue Lake' and 'Kentucky Wonder.' The safest time to plant pole beans--either seeds or small plants--is after the last expected spring frost once the soil has warmed. You can also start pole bean seeds indoors about four to six weeks earlier, if desired.
Choose a location to plant green pole beans that receives at least six hours of direct sunlight a day and has soil with good water drainage. Avoid planting the beans where water often puddles and in areas where the soil is consistently moist, such as near a water source. To improve water drainage in sandy soils, till the garden 12 inches deep and mix in approximately 4 inches of organic matter (e.g., compost or peat moss). For clay soils, mix in about 2 inches of organic matter and 2 inches of coarse sand.
Incorporate 1/2 cup of 5-10-10 (nitrogen-phosphorus-potassium) granular fertilizer for every 25 linear feet you plant with beans. Mix it into the top 6 inches of soil.
Plant pole bean seeds 1 to 1 1/2 inches deep about 2 inches apart (thin later to every 6 to 10 inches). Plant small pole bean plants 6 to 10 inches apart. Space more than one row 3 to 4 feet apart. Water the newly planted seeds or plants with 1 inch of water.
Construct one support for every two to three plants. The support should be about 6 to 7 feet tall and comprise three poles tied at the top to create a triangular shape. You can also put a pole every 6 feet and attach and connect the poles at 2, 4 and 6 feet with wire. Train the plants to grow up the support. Tie loosely with twine, if possible, but if you use rough poles (not smooth), the plants will naturally adhere to the poles.