How to Grow Common Beans

By Marie Iannotti 

Common bean plants (Phaseolus vulgaris) are either pole bean varieties that grow long vines or low-growing bush beans. Most varieties are green, but there are also purple, red, yellow, and streaked beans. Common beans are several inches long and either round or flattened in shape. Bean plants are annual vegetables that grow quickly and are best planted in the spring. The flowers appear about two months after planting. Harvest time varies greatly, depending on the type of bean. Note that the seeds of raw or undercooked beans can be toxic to people1 and animals2.

How to Plant Common Beans

When to Plant

The most important rule of growing common beans is not to plant too early. Plant in the spring after all danger of frost has passed. Seeds sown too early can rot in cold, damp soil, and the plants need warm weather to thrive.

Selecting a Planting Site

Choose a planting site that gets lots of sun and has organically rich soil with sharp drainage. Make sure there are no tall shrubs or trees nearby that will create too much shade for the beans. Beans also can be grown in raised beds and containers.

Spacing, Depth, and Support

In general, plant seeds about an inch deep, and position nursery plants at the same depth they were in their previous container.

• Bush beans can be planted in rows 2.5 to 3 feet apart, with seeds placed 1 to 2 inches apart. After the plants germinate, thin the seedlings to 3 to 4 inches apart.
• Pole beans need some type of support on which to grow. The support should be 6 to 8 feet tall. Be sure the support is in place before you seed. Space supports roughly 3 to 4 feet apart.

Common Bean Care

Light

Beans need full sun for the best yield. Full sun also helps to keep the plants dry and less likely to be affected by certain issues, such as fungal diseases.

Soil

Beans like organically rich loamy soil with a slightly acidic pH. Good soil drainage also is key. Remove weeds prior to planting to prevent competition for soil nutrients and moisture. As the beans grow, weed carefully around the plants, as their shallow roots can be easily damaged.

Water

Common beans need 1 inch of water per week. Use a drip irrigation system for supplemental watering to avoid splashing soil onto the leaves, which can lead to soil-borne diseases. To determine whether the plants need water, stick your finger about 1 inch into the soil near the base of the plant. If the soil is dry, it's time to water. Plants that are underwatered will stop flowering. Beans have shallow roots, and mulching can help to keep them cool and preserve moisture in the soil.

Temperature and Humidity

Common beans germinate best when the soil temperature is between 70 and 80 degrees. If the soil temperature is below 60 degrees, seeds will germinate more slowly and are susceptible to rot. The plants grow best when the air temperature is between 65 and 85 degrees. Beans tend to stop flowering in the extreme heat of summer. But keep them well-watered, and they will resume flowering and production when temperatures cool. Moreover, common beans grow in all humidity conditions if properly watered.

Fertilizer

As legumes, beans fix nitrogen in the soil, so avoid a high-nitrogen fertilizer. Instead, use a 10-20-10 fertilizer to feed the plants throughout the growing season, following the product directions. Pole beans produce over such a long period that they also will benefit from a side dressing of compost about halfway through their growing season.

Pollination

Bean plants are self-pollinators.

Types of Common Beans

There are several types of common beans, including:

• 'Kentucky Wonder': This old pole variety of string bean is prized for its flavor.
• 'Bountiful': This is an early producing, stringless heirloom bush bean.
• 'Golden Wax Bean': This is a soft-textured, yellow bush bean.
• 'Royal Burgundy': An early producing bush bean, it has purple pods that turn green when cooked.
• 'Romano': This classic broad, Italian-style, bush or pole bean has a meaty flavor.

Common Beans vs. Peas

Bean and pea plants can look somewhat similar. However, pea stems are usually hollow while bean stems are typically solid. Plus, the peas themselves are generally round while beans can come in a variety of shapes. 

Harvesting Common Beans

Harvesting beans is an ongoing task, and the more you pick, the more beans the plants will set. You can start to harvest anytime after the beans form. Gardeners usually harvest the beans when they are young and tender, about the size of a small pencil. Overly mature beans can be tough and stringy.

In general, bush beans are ready to pick in 50 to 55 days after planting. Pole beans will take 55 to 65 days, depending on the variety. Check the packet to be sure your choice will have time to mature in your growing season. Harvest by gently pulling each bean from the vine or by snapping them off at the vine end. Be careful not to damage the plant when harvesting. You can cook the beans right away or blanch and freeze them. They can keep in the freezer for up to a year.

How to Grow Common Beans in Pots

Growing beans in a container can be helpful, especially when it comes time to regularly harvest your crop. As long as the container gets enough sunlight, you can place it in a spot that’s convenient for you to visit regularly. 

Choose one of the smaller bean varieties if you wish to grow them in containers, and be sure to give pole beans a support structure on which to grow. Aim for a container that is at least a foot deep with ample drainage holes. An unglazed clay container is ideal because it will allow excess soil moisture to evaporate through its walls. Wood barrels also can make good planters. 

Propagating Common Beans

Bean plants are propagated via seed. Because the plants are annuals, this is an inexpensive way to ensure you have new plants each year. Here’s how to save the seeds:

1. Harvest seed pods from a healthy bean plant once the pods have dried and become brittle.
2. Break open the pods to release the seeds.
3. Store the seeds in a dark, dry, cool spot within an airtight container. They should be viable for three to four years and can be planted in the spring after the threat of frost has passed.

How to Grow Common Beans From Seed

Bean seeds are generally direct sown in the garden, as they dislike being transplanted. Their roots are shallow and easily damaged. If you want to start beans inside, plant them in biodegradable pots that can be planted into the garden once the weather has warmed.

Potting and Repotting Common Beans

A quality potting mix that’s labeled for vegetables is usually ideal for growing beans. As long as you plant in a large enough container, you won’t have to repot these annuals during the growing season and disturb their roots.

Common Pests and Plant Diseases

Several animal pests love bean plants, including:

• Mexican bean beetles will eat the flowers, the beans, and especially the leaves.
• Spider mites pierce the leaf surface and suck the sap, often causing leaves to die.
• Japanese beetles and aphids may also attack bean plants.
• Bean leaf beetles can girdle the stems near the soil line and chew holes in the plant's leaves.
• Deer and groundhogs will eat entire bean plants, and fencing is necessary to stop them if they are prevalent in your area.

Furthermore, fungal diseases, such as Alternaria leaf spot, can be a problem in damp conditions. Other diseases, including white mold, bean rust, and mosaic virus, can also affect bean plants. Help prevent diseases by keeping the vines dry. Also, don't overcrowd the plants, and provide plenty of good air circulation. You can look for plant varieties that are bred for disease resistance.