When and How To Plant and Harvest Green Beans In Iowa

Green beans are intriguing vegetables to grow if you have space. They’re easy to manage and don’t take up much room in the garden.

However, with several aspects involved when planting green beans, it can be hard to decide how you can proceed with this crop in Iowa. Lucky for you, this post has got the answers for you below.

When To Plant Green Beans In Iowa

when to plant green beans in iowa

Green beans are a warm-season crop. You should plant them in early spring after all danger of frost has passed and the soil has warmed. In most cases in Iowa, this will be April or May. Ensure the soil is light and well-draining with a pH level between 6 and 7.

Green beans will grow best when planted in well-drained loamy soil rich in organic matter. The soil pH should range from 6.0 and 7.5. You can conduct soil testing to help determine what is needed to achieve this balance. You can add fertilizer to supply necessary nutrients if it does not affect the pH levels too much.

For green beans to grow well, soil temperatures should be about 50 degrees Fahrenheit. However, most Iowa will have a shorter growing season than that and may need more time to produce good yields.

Green beans prefer cool weather but will still grow in temperatures as low as 32 degrees Fahrenheit.

However, the upper-temperature limit for green beans is about 90 degrees Fahrenheit (32 Celsius). This temperature limit is not too high compared to other vegetables that can tolerate temperatures over 100 degrees F.

How To Plant Green Beans In Iowa

when to plant green beans in iowa

Plants need to be spaced 6–8 inches apart. Deep-rooted varieties work best, especially when planted in hills or mounds.

The plants direct the trenches where beans are planted in different directions to space. Square up the beds, grade them into hills, or mark off a circular path for plants, and insert trellises at even intervals for each planting direction.

Seed about 1 pound of seed per 1,000 square feet of the ground.

The seeds germinate in 7–10 days with heat from solar and natural sunlight and soil temperature. When the seedlings are approximately 6 inches tall, apply 1/2 cup of a complete fertilizer with minor elements such as magnesium, manganese, and boron per 20 feet of row; or use a fertilizer that contains 4-1-2 or 4-2-2 analysis with nitrogen in the first number. Deep-rooted varieties do not need a starter fertilizer application.

Vigorous plants can reach 12 inches in height and produce beans for at least five weeks. At this point, you should thin the green bean plants to the sturdiest plants along the row.

Plants thinned out often develop a yellowing between the leaves caused by fungus. You can do thinning by leaving 1–2 inches between plants so that sunlight can reach all of the plant’s leaves, and subsequent beans will have room in the row.

When To Harvest Green Beans In Iowa

Green beans might be ready for harvesting within 50 to 60 days after planting. The average yield will be about 30 pounds per acre for this type of bean plant. These plants will also produce 10-12 pods per plant, with one pod typically containing 4-5 seeds.

If you choose to plant French-cut green beans, you must make sure that you harvest them before the first frost of fall. The average yield is around 10 pounds per acre, with the plants maturing in late August or September with a single plant containing 8-10 pods.

You should begin checking the plants as they grow and make a note when 50-60% of the pods have reached their mature stage and turn yellow.

Typically, you will see yellowing first on the bottom plants in a planting bed, but it’s not uncommon for it to occur later than that on top plants due to larger leaves blocking smaller ones from getting more sunlight. Once you see yellowing, you can harvest the whole row or just a small section of each row.

Challenges With Growing Green Beans In Iowa

Beans Are Easily Affected By Pests And Diseases

The first challenge when growing green beans in Iowa is that they are very susceptible to many pests and diseases. Polling beetles are the most common insect pest of green bean plants, and they are found across the state of Iowa.

The works of pollinating insects like the honey bee are significant to the plants, so it is vital to ensure they are present.

The bugs do not eat the beans, but they can make them impossible to grow. When ground beetles first appear, they will usually feed on other plants.

They move toward green bean plants when they are 5/16 inches long and continue moving toward them until they reach 1/4″ long. As soon as beetles start feeding on beans, it is time to treat the plants with pesticides or insecticides that can kill the bugs quickly.

You can do that by spraying the plants with bifenthrin or permethrin.

Another challenge to growing green beans in Iowa is the risk of bean aphids. The green bean aphid is the most common aphid to attack beans and often turns various colors from red, white and black.

Aphids feed on the undersides of plants, which can cause leaves to curl and yellow. If left uncontrolled, aphids can cause severe damage to a plant or crop. Luckily for farmers in Iowa, several insecticides control these pests.

Aphids are also more abundant when it frequently rains because they prefer growing in humid and wet environments.

Aphids will also travel to areas where it is warmer and drier, so growers should take steps to prevent them from spreading in the same way that farmers use beneficial insects to control pests and diseases.

Beans Need Lots Of Space.

Green beans are relatively slow-growing plants, so they require a lot of room to produce. That presents a challenge if you grow green beans in a contained area like containers, raised beds, or tomatoes that require more garden space. In reality, they may need that much more space than you wish to give them because green beans will spread and grow very slowly.

Beans Require Lots Of Water

All kinds of beans rely on rainfall to water their roots and soaking them every day can be problematic in areas with hot, dry weather. However, it may not be a massive challenge for you if you live or garden in a place where rainfall is usually fairly regular (i.e., Oklahoma, Missouri, Kansas, Texas).

However, it may be a challenge for you if you live in an area like Iowa, where rainfall is not consistent. Instead of flooding the bean beds with water every day, you may find that the beans need irrigating only once per week.

Poor Weather Conditions

One of the biggest challenges when growing green beans in Iowa is the weather. Due to cold temperatures, farmers must be cautious with choosing and securing their seeds.

Cold soil will damage seeds as they grow, making it essential for farmers to ensure their soil temperature is warm enough before planting. Larger beans from hot weather are more damaged than smaller beans produced in a cool climate like Iowa.

When to plant green beans in Iowa: Conclusion

When you are planting and harvesting vegetables such as tomatoes, cucumber and green beans in Iowa, there are some things you should know to maximize your harvest. There is a season for planting, harvesting, and picking.

Green beans, legumes and peas are warm-season crops that you should plant in April or May. If the ground is too wet from last year’s crops, wait until it dries out.

The season when you can harvest the green beans depends on where they are growing.

Related Article: How and When to Plant and Harvest Onions in Iowa