In Kansas, the best time to plant green beans is after the last frost date when the soil temperature reaches around 55-60°F. This typically means planting in early to mid May in most parts of Kansas. For a fall crop, green beans can be planted again in early August to early August to get established before the first frost in October. More specifically:

• Last frost dates vary by location but are generally in early May. For example, Topeka's last frost date is around May 4th.
• Green beans should be planted after danger of frost has passed and the soil is warm.
• Fall green beans can be planted in late July or early August for a late-season harvest.
• Green beans require full sun and well-draining soil and are usually direct-seeded about 1 inch deep in rows 18 inches apart.
• Multiple plantings spaced a few weeks apart can provide a continuous harvest.

So for most Kansas gardeners, plant green beans in May after frost risk is gone for spring harvest and again in late July to early August for fall harvest.

If you would like planting dates tailored to a specific city in Kansas, I can provide that as well.