Green beans, Phaseolus vulgaris, are also commonly known as snap beans, haricot, bush beans, string beans, and pole beans. This plant has become one of the most widely used vegetables in the garden, not only grown for its health benefits, but also because they are prolific producers and very easy to grow.
After germination, most green beans are ready to harvest in 45 to 60 days, making them a favorite for a steady yet quick harvest. It is recommended that for each household member you grow about four to eight bean plants. In smaller gardens it is best to grow pole beans to help save space.
Growing Green Bean Plant photograph by J Driskell (CC: https://www.flickr.com/photos/nogranddesign/)
Snap or green beans are tender annuals grown for their immature pods that are edible. They can grow as either vines or bushes and both color and pod sizes are variable. Pods can range from three or four inches up to six to eight inches or more (8 – 25 cm) and colors can be green, yellow (Wax beans), purple, or speckled. Leaves normally consist three leaflets, have a medium texture and are medium green; flowers are white, yellow, or lavender; the pods can be round or flat. Blooms usually occur from mid-late summer.
The bush bean variant can be harvested within 45 to 60 days, grows to a height of two or three feet (60 – 90 cm) and mature earlier than pole beans. Spread is typically from 1 to 2 feet (30 – 60 cm).
The pole bean variants take 60 to 85 days to harvest, and can grow up to eight feet (2.4 m) in height. Pole beans produces more beans per plant compared to bush beans and require a trellis or stake for support. It is also possible to grow Jerusalem Artichokes as an interesting support for Pole beans.
Information on Growing Broad Beans.
Green beans grow best in full sun. Beans that were grown in partial shade normally produce harvests with lower yields. A loose, well-drained soil rich in organic matter with soil pH of 6.0 to 6.8 is best for green beans to grow at their best, though they will also grow well in a soil with average fertility.
Ideally, the planting bed should be prepared in advance using plenty of aged compost to provide plants with a sufficient source of nutrients. Avoid planting beans where green manure crops have previously grown or where soil nitrogen is very high—these lead to plants producing greater green foliage but fewer beans.
Green beans are best sown one to one and a half inches (2.5 to 4 cm) deep. The bush beans should be planted from two to four inches (5 – 10 cm) apart and set in rows 18 to 24 inches (45 – 60 cm) apart.
Pole beans are planted four to six inches (10 – 15 cm) apart with set rows spaced at 30 to 36 inches (75 – 90 cm). Use supports such as poles, trellis, or stakes in place at planting time and remove weaker seedlings by cutting them off at the soil level with scissors, being careful not to touch or disturb the roots of other seedlings. Five to six seeds of pole beans can also be planted in inverted hills spaced at 40 inches (100 cm) apart. Thin seedlings to four to six inches (10 – 15 cm).
Green Bean pods by 16:9clue (CC: https://www.flickr.com/photos/53255320@N07/)
Beans are tender annual plants that are best grown in temperatures from 50° and 85°F (10 – 29°C). However germination is poorer in cooler temperatures, typically taking over two weeks below 60°F (15°C) and eight days at more optimal germination temperatures (70 to 85°F; 21 – 29°C). Beans of up to five years old can be sown in the garden when the soil temperature had warmed, when there is no longer a chance of a frost; yield is reduced and damage occurs if subjected to cold air. Ideal temperature of the soil should be 60° to 85°F (15 – 29°C). It is best to sow seeds directly as beans do not like to be transplanted; do not soak beans as this can damage them.
Inoculation of beans with a rhizobium bacteria helps to improve yields in plots where beans have not previously been grown.
If attempting to start off indoors (not recommended) then plant beans about three or four weeks before the average last frost date of the spring season in a biodegradable peat or paper pot that can be set in soil without causing damage to roots.
Propagate successive crops of bush beans every two weeks until mid-late July for a continuous harvest throughout the growing season. Beans, no matter the variety, can continuously grow in the garden until the first frost in fall. Beans can be sown in autumn, in preparation for a winter harvest in mild-winter regions.
Grow beans in soil that is moistened evenly, about 1 inch (2.5 cm) per week. When soil moisture is relatively high at sowing, cracked bean seeds and poor germination can occur. Avoid soaking the beans prior to planting and after sowing, do not over water the plant. Always keep the soil evenly moist throughout the formation of flowers and pods. Prevent disease by avoiding getting water on foliage. Provide a mulch to conserve moisture when soil temperatures exceed 60°F (15°C), this should be done after the second set of true leaves have developed.
The ideal fertilizer for green beans is aged garden compost and the plant does not need extra nitrogen so avoid using nitrogen-rich fertilizers or green manure fertilizers.
Carefully cultivate around beans to avoid disturbing the root system, especially shallow ones. Do not carry wet beans as this can help spread fungus spores. Before planting pole beans, set trellises, stakes or poles in place being careful to select tall enough supports for the variety of beans being grown.
If pods are deformed it is a sign of them not being given enough water, being grown in a poor soil, or having their flowers attacked by insects during blooming.
Flea beetles, bean beetles, aphids, leafhoppers, seedcorn maggots, and spider mites can all attack Beans. Leafhoppers, mites, and aphids can be sprayed away with the use of insecticidal soap or simply by blasting water from the hose.
Look for infestations and eggs and crush them between the thumb and finger. Always keep the garden free of debris and clean to prevent pests from destroying the garden.
Common diseases include bacterial blights, Bean common mosaic virus (BV-1; NY 15); and White mold. To help prevent these diseases it is important to avoid getting water on the foliage when watering (it is best to water beans early in the day as this will allow any excess water to quickly dry), avoid overcrowding (to increase air-circulation), rake away any fallen leaves and fruits, grow resistant varieties, eliminating weeds, and rotate crops. Only ever work with beans when they are dry.