Beans are a staple in almost every vegetable garden. Edible beans come in many sizes, shapes, and colors and include green beans, pinto beans, lima beans, edamame (soybeans), cowpeas, kidney beans, and others. Although Iowa is known for growing soybeans, there are many other types of beans that grow well in the home garden. In this article, horticulturists at Iowa State University Extension and Outreach answer frequently asked questions about growing beans in the home garden.
Until when can I plant green beans?
Green beans (also called snap beans, string beans or wax beans) are a warm season vegetable and should be planted after danger of frost has passed. In central Iowa, it is generally safe to start planting green beans in early May. If harvested frequently, the plants should produce well for several weeks. The last practical date for planting green beans is August 1.
Some of my green beans got too big and bumpy. Are they still edible?
Although the large, bumpy pods are still edible, they are not as flavorful. Green beans (also called snap, string or butter beans) are meant to be eaten as immature pods containing small, undeveloped seeds. When the seeds inside the pod are too large and overripe, the bean pod becomes tough and stringy and not as palatable. The ripe bean inside the pod of a green bean can be peeled and used fresh like fava, butter, or fava beans, but the flavor will likely be inferior.
I planted lima beans this spring, but the plants only produced a few pods. Why? In the Midwest, yield is largely determined by weather conditions. Lima beans grow best when temperatures are between 70 and 80 degrees Fahrenheit. They also need 1 inch of water per week (rain or irrigation) during flowering and pod development. Hot, dry conditions during flowering can cause many flowers to drop without forming pods. Excessive nitrogen fertilization promotes lush growth but can also inhibit pod formation.
Although both bush and pole lima beans are available, bush-type varieties generally perform better than pole varieties in Iowa. Suggested bush-type varieties for Iowa include: ‘Fordhook 242’ (large greenish white seeds, heat tolerant) and ‘Henderson Bush’ (small white seeds, early maturing).
Which is more productive, the green bean or the pole bean?
In general, string beans are more productive than bush beans simply because they are taller plants. A 10-foot row of bush beans spaced 2 inches apart can produce between 4 and 5 pounds of green beans, depending on cultivar and growing conditions. Under the same conditions, a 10-foot row of green beans spaced 4 inches apart (gardeners typically space green beans wider than the bush) can yield about 8 pounds of green beans, depending on the variety. Planting green beans seems like an obvious choice since you can sow fewer seeds and get more green beans. But dwarf beans have the great advantage of not requiring the construction of a trellis, teepee or other form of support, which reduces material costs, labor and time spent in the garden.
Will my green beans pollinate nearby soybeans?
Beans produce perfect, self-fertile flowers, so they pollinate easily and easily. Only beans of the same species are capable of cross-pollination. Thus, green beans (Phaseolus vulgaris) can cross with other varieties of beans of the same species, but they cannot cross with soybeans (Glycine max) which belong to a different genus.
If you have two bean varieties of the same genus that you’re worried about cross-pollinating because you plan to save the seeds to plant next year, just plant the different varieties 10 feet apart to avoid almost anything. cross-pollination potential.