Runner beans, scientifically known as Phaseolus coccineus, are a vigorous and productive climbing bean variety. They belong to the Fabaceae family, which includes other legumes like peas, lentils, and soybeans. Known for their showy flowers and long, tender pods, runner beans are both ornamental and edible, making them a popular choice for gardeners. They are widely grown in the UK and other temperate regions, where they thrive in cooler summer climates.
Runner Beans Overview
Botanical Background and Global Popularity
Runner beans are native to Central and South America, where they have been cultivated for centuries. They were introduced to Europe in the 17th century and have since become a staple in British and European gardens. Runner beans are particularly valued for their dual purpose as both an ornamental and a food crop, producing vibrant red, white, or bi-colored flowers that attract pollinators, as well as long, fleshy pods that are harvested for food. The beans inside the pods can also be dried and used in soups and stews.
Edible Parts and Culinary Uses
The primary edible part of the runner bean plant is its long, flat pods, which are typically harvested when they are young and tender, about 15 to 25 cm (6 to 10 inches) in length. These pods are commonly sliced and cooked as a vegetable, often boiled, steamed, or stir-fried. The beans inside the pods are also edible and can be used fresh or dried. Fresh runner beans are versatile and can be added to salads, casseroles, and other dishes. The dried beans are rich in protein and can be stored for use in soups, stews, and other long-cooking recipes.
Suitable Planting Season
Optimal Time for Sowing Runner Beans
Runner beans are warm-season crops that thrive in mild, temperate conditions. The best time to plant runner beans is in late spring, once the soil temperature has warmed to at least 12°C to 15°C (54°F to 59°F). In temperate regions, runner bean seeds can be sown directly into the garden after the last frost date. Alternatively, seeds can be started indoors 2 to 4 weeks before the last frost and transplanted outdoors once the danger of frost has passed.
Seasonal Considerations for Different Climates
In cooler climates, runner beans should be planted during the warmest part of the year, typically from late spring to mid-summer. In warmer climates, runner beans can be grown in early spring or late summer to avoid the hottest months, which can cause the plants to become stressed and less productive. Succession planting, or sowing seeds every few weeks, can help ensure a continuous supply of fresh runner beans throughout the growing season.
Ideal Soil Type
Soil Composition and Texture
Runner beans grow best in well-draining, fertile soil with a light, crumbly texture. The ideal soil should be rich in organic matter, such as compost or well-rotted manure, which provides the nutrients necessary for healthy plant development. Loamy soil is ideal for runner beans, as it retains moisture without becoming waterlogged. Heavy clay soils can be problematic, as they tend to hold too much water, leading to root rot and other issues. If your soil is heavy or compacted, consider amending it with organic matter to improve its structure and fertility.
Soil pH and Fertility
Runner beans prefer a slightly acidic to neutral soil pH, ideally between 6.0 and 7.0. Maintaining the correct pH is important for nutrient uptake, particularly for nitrogen, which runner beans fix naturally through symbiosis with nitrogen-fixing bacteria. Regular soil testing can help you monitor and adjust the pH as needed. Runner beans are moderate feeders, so it is beneficial to incorporate a balanced organic fertilizer or compost into the soil before planting. Side-dressing with compost or applying a liquid fertilizer during the growing season can also help maintain soil fertility and support vigorous growth.
Sowing Tips
Preparing the Soil for Sowing
Before sowing runner bean seeds, it is essential to prepare the soil thoroughly. Start by removing any weeds, rocks, and other debris from the planting area. Loosen the soil to a depth of about 30 cm (12 inches) and incorporate a generous amount of compost or well-rotted manure to improve fertility and drainage. If you are planting in raised beds, make sure the soil is well-drained and has a fine, crumbly texture that allows the seeds to germinate easily. For best results, lightly moisten the soil before sowing to create an ideal environment for seed germination.
Sowing Technique and Seed Spacing
Runner bean seeds can be sown directly into the garden bed or started indoors for later transplanting. To sow directly, plant the seeds about 5 cm (2 inches) deep in rows spaced 45 to 60 cm (18 to 24 inches) apart. The seeds should be spaced 15 to 20 cm (6 to 8 inches) apart within the row to allow for sufficient plant development. If you prefer to start seeds indoors, sow them in pots filled with a high-quality seed-starting mix, and transplant the seedlings when they are about 10 to 15 cm (4 to 6 inches) tall and have at least two sets of true leaves.
Protection and Germination
Runner bean seeds typically germinate within 7 to 14 days, depending on soil temperature and moisture levels. To protect the seeds and encourage even germination, consider covering the seedbed with a thin layer of mulch or a row cover, especially in cooler climates. This helps maintain consistent soil moisture and temperature, reducing the risk of poor germination or seedling damage. Once the seedlings have emerged, thin them to a spacing of 15 to 20 cm (6 to 8 inches) apart to allow for proper growth and air circulation.
Is Year-Round Harvesting Recommended?
Feasibility of Continuous Harvest
Runner beans are typically grown as annuals, with a single harvest period at the end of the growing season. Year-round harvesting is not usually recommended for runner beans, as they require a specific growing season to reach maturity. However, in regions with mild climates, you can stagger your planting times or use succession planting techniques to extend the harvest period.
Succession Planting for Extended Harvest
Succession planting is an effective strategy for extending the runner bean harvest over several months. By sowing seeds every few weeks, you can ensure a steady supply of fresh runner beans without overwhelming yourself with too much produce at once. This method works particularly well in regions with variable climates, as it allows you to adjust planting times based on weather conditions. In cooler climates, consider using a cold frame or row cover to protect the plants from frost and extend the harvest into early autumn.
Growth Speed Reference
Germination and Early Growth
Runner beans are relatively fast-growing plants, particularly when grown in optimal conditions. Seeds typically germinate within 7 to 14 days, and the seedlings are hardy enough to tolerate light frosts. During the first few weeks after germination, runner bean plants focus on developing a strong root system and producing their first set of true leaves. The plants grow rapidly in warm, moist conditions, with flowering beginning around 6 to 8 weeks after planting.
Time to Maturity and Harvest
Depending on the variety and growing conditions, runner beans are usually ready to harvest within 60 to 90 days from sowing. The pods can be harvested at various stages, from small, tender beans to larger, more mature pods. For the best flavor and texture, it is recommended to harvest runner beans when the pods are about 15 to 25 cm (6 to 10 inches) long and still tender. Regular harvesting encourages the plant to produce more pods and extends the harvest period.
Considerations for Different Varieties
Different runner bean varieties may have slightly varying growth rates and harvest times. For example, early-maturing varieties like ‘Scarlet Emperor’ or ‘White Lady’ are often ready for harvest in as little as 60 days, while slower-maturing varieties like ‘Polestar’ may take up to 90 days to reach full maturity. When selecting a variety, consider your local growing conditions and the desired harvest time. Climbing varieties are ideal for training up trellises or poles, while bush varieties may be better suited for smaller gardens or container growing.
Temporary Shade for Hot Weather
Heat Tolerance and Risks
Runner beans thrive in mild, temperate conditions but can suffer from heat stress if exposed to intense sunlight for prolonged periods, especially during the flowering and pod-setting stages. In regions where summer temperatures regularly exceed 30°C (86°F), runner beans may benefit from temporary shading, particularly during the hottest part of the day. Providing some form of shade can help prevent the flowers from dropping and ensure better pod development.
Methods for Providing Shade
If you are growing runner beans in a hot climate or during the peak of summer, consider using shade cloth to reduce the intensity of sunlight. A shade cloth with 30% light reduction is usually sufficient to protect the plants from excessive heat while still allowing enough light for photosynthesis. Alternatively, planting runner beans in an area that receives morning sun and afternoon shade can help mitigate the effects of high temperatures. For container-grown runner beans, simply moving the pots to a shaded area during the hottest part of the day can also be effective.
Watering Tips
Importance of Consistent Moisture
Runner beans require consistent moisture to produce healthy, tender pods. Inconsistent watering can lead to poor pod development, bitterness, and increased susceptibility to pests and diseases. It is important to keep the soil evenly moist but not waterlogged, particularly during the early growth stages and as the plants begin to flower and set pods. Overwatering should be avoided, as it can lead to root rot and other fungal diseases.
Watering Technique
For best results, water runner beans deeply and regularly, focusing on the root zone. Drip irrigation systems or soaker hoses are ideal, as they deliver water directly to the soil without wetting the foliage, reducing the risk of disease. If watering by hand, apply water slowly at the base of the plants to allow it to penetrate deeply into the soil. Mulching around the plants with organic material such as straw, compost, or shredded leaves can help retain soil moisture and reduce the need for frequent watering.
Mulching to Retain Moisture
Applying a mulch layer of 5 to 7.5 cm (2 to 3 inches) around the base of the plants can help retain soil moisture, suppress weeds, and keep the soil cool. Mulch also helps to reduce water evaporation from the soil surface, which is particularly beneficial during hot, dry periods. Organic mulches such as straw, grass clippings, or shredded leaves are ideal, as they also contribute to soil fertility as they break down.
Recommended Watering Timing
Best Times to Water Runner Beans
The best time to water runner beans is early in the morning, allowing the soil to absorb the water before the heat of the day. Morning watering ensures that the plants have access to moisture throughout the day, which is especially important during hot weather. Watering in the morning also helps reduce the risk of fungal diseases, as the foliage has time to dry out before nightfall. In particularly hot or dry conditions, a second watering in the late afternoon may be beneficial, but avoid watering too late to prevent the plants from staying wet overnight.
Adjusting Watering Based on Weather
Watering frequency should be adjusted based on weather conditions. During cooler, wetter periods, less frequent watering is needed, while in hot, dry weather, more frequent watering may be necessary to maintain consistent soil moisture. Monitoring the soil moisture level regularly and adjusting your watering schedule accordingly will help ensure that your runner bean plants receive the right amount of water at the right times.
Watering Frequency Reference
General Guidelines
Runner beans typically require watering once or twice a week, depending on the weather and soil conditions. In sandy soils, which drain quickly, more frequent watering may be necessary, while in heavier soils, less frequent watering may be required. The key is to keep the soil consistently moist but not waterlogged, particularly during the growing season when the pods are being produced.
Indicators of Proper Watering
To determine whether your runner bean plants are receiving enough water, check the soil moisture level at a depth of about 15 cm (6 inches). If the soil feels dry at this depth, it is time to water. Additionally, wilting leaves, particularly in the early morning or evening, can be a sign that the plants need more water. However, if the leaves remain wilted during the heat of the day but recover by evening, it may be a normal response to high temperatures rather than a sign of water stress.
Pest and Disease Control
Common Pests Affecting Runner Beans
Runner beans are relatively hardy but can be affected by a few common pests, including aphids, black bean aphids, and slugs. Aphids are small, sap-sucking insects that can weaken plants and spread diseases. Black bean aphids are a specific type of aphid that often targets runner beans, feeding on the undersides of leaves and stems. Slugs are another common pest, especially in wet conditions, and can chew holes in the leaves and pods.
Integrated Pest Management Strategies
To manage these pests, gardeners can use a combination of cultural, mechanical, and biological control methods. Regular monitoring and early intervention are crucial. Insecticidal soaps or neem oil can be effective against aphids, while slug traps or barriers can help reduce slug populations. Encouraging beneficial insects, such as ladybirds and lacewings, can also help keep pest populations in check. Additionally, maintaining healthy, well-watered plants can make them less susceptible to pest infestations.
Common Diseases and Prevention
Runner beans are also susceptible to several fungal diseases, including powdery mildew, rust, and halo blight. Powdery mildew appears as a white, powdery coating on the leaves, while rust causes orange or brown pustules on the leaves and stems. Halo blight is a bacterial disease that causes yellowing and browning of the leaves, often surrounded by a “halo.”
To prevent these diseases, ensure good air circulation by properly spacing plants and avoiding overhead watering. Crop rotation and removing plant debris at the end of the season can also reduce the likelihood of disease recurrence. In cases where fungal diseases are detected early, fungicidal sprays can help manage the outbreak.
Seed Preservation and Storage Methods
Harvesting and Preparing Seeds
Runner bean seeds can be saved from mature pods that have fully dried on the plant. To save seeds, allow the pods to mature and turn brown on the plant. Harvest the pods, remove the seeds, and spread them out on a paper towel to dry further in a cool, well-ventilated area. Once the seeds are fully dry, they can be stored for future planting.
Optimal Storage Conditions
Store runner bean seeds in an airtight container in a cool, dry, and dark place. A temperature of around 5°C to 10°C (41°F to 50°F) is ideal for seed storage. Properly stored runner bean seeds can remain viable for up to 3 years. Labeling the container with the date of harvest and the variety name can help you keep track of your seed inventory.
Preserving Edible Parts and Storage Duration
Post-Harvest Handling
After harvesting, runner beans should be handled gently to avoid bruising, which can lead to rapid deterioration. Fresh runner beans can be stored in the refrigerator for up to a week. To store them, place the pods in a plastic bag with ventilation holes or wrap them in a paper towel to absorb excess moisture. If you plan to use the runner beans within a few days, they can be kept at room temperature.
Short-Term and Long-Term Storage
For longer storage, runner beans can be blanched and frozen or dried. To freeze runner beans, wash and trim the pods, then blanch them in boiling water for 2 to 3 minutes. Immediately cool them in ice water, drain well, and pack them in airtight containers or freezer bags. Frozen runner beans can be stored for up to 10 to 12 months. Dried beans can be stored in an airtight container in a cool, dry place for several months.
Nutritional Content of Edible Parts
Nutritional Breakdown
Runner beans are highly nutritious, offering a good source of vitamins A, C, and K, as well as folate and dietary fiber. They are low in calories and contain antioxidants that help protect against oxidative stress and inflammation. The beans inside the pods are also rich in protein and can be used as a plant-based protein source.
Health Benefits and Comparisons
In addition to their high nutrient content, runner beans offer several health benefits. The high levels of dietary fiber in runner beans aid in digestion and help maintain healthy blood sugar levels. The vitamin C in runner beans supports immune health, while vitamin K is essential for bone health and proper blood clotting. Compared to other legumes, runner beans are particularly valued for their tender texture and mild flavor, making them a popular choice for those seeking to add more vegetables to their diet.
