Inoculants help the plants fix atmospheric nitrogen, making this key nutrient more availabe. Edamame have few pests and diseases. In the South, the bean leaf roller can hamper growth, and powdery mildew can rot the beans on the plant before harvest. However, these problems are rarely sever enough to reduce yields or require controls. Harvesting edamame at the right time is critical.
Beans reach their maximum sweetness about a month after flowering.
The quality is best when beans fill 85 percent of the pod, which should be bright green, similar to snow peas in color. You can pick individual beans off the plants or pull the whole plant out of the ground when most of the beans are mature, and then pick the beans later. Be careful when harvesting individual beans. The stems are brittle, and I've broken a few when trying to harvest too fast.