Well drained, warm soil in full sun is best. Use 1 cup of balanced organic fertilizer for every 3m (10′) of row. Too much nitrogen in fertilizer or manure is often the cause of poor pod set and delayed maturity. If beans flower but do not set pods, the cause can be zinc deficiency. Try spraying the plants with kelp based fertilizer. Wet leaves on crowded plants are subject to diseases. Thin plants to increase air circulation and avoid touching the leaves while they are wet.