Introduction

Beans come in all shapes, colours and sizes. Climbing runner beans and French beans as well as the self-supporting broad beans. Most beans are grown as annuals but some are perennial. It is possible to over winter some varieties, but very little is to be gained from it. Beans are cool season crops, but few will tolerate frost.

Broad (Fava) Beans

Broad beans vary in height from the large 1.5m (5ft) monsters, down to the dwarf 30cm (12in) ones. Beans grow best in the cooler parts of the UK, some young plants have survived temperatures of -10°C (14°F), but the ideal temperature is below about 15°C (59°F). The newer varieties, however, will tolerate slightly higher temperatures. The seeds are best sown in the spring (February and March) in an open sunny site, or sown in the autumn in a sheltered site for an overwintering crop.

Sowing the Seed (Do not start off in the greenhouse)

One of the biggest causes of non or poor germination is due to the seed being started off in a hot greenhouse. The seed should be sown in situ in the spring, as soon as the land is workable. If you live in a sheltered area and require an earlier crop you can sow again in situ in the autumn, or in colder areas plant in 7.5cm (3in) pots in late winter. Keep the young plants cool and transplant out as soon as possible in the early spring. Incorporating well-rotted manure and using black plastic over the bed in the winter will help warm the soil, so sowing direct is possible. Seeds sown direct in warmed soil tend to catch up with the young plants very quickly, so direct sowing is preferred and generally less costly and time consuming.

Sow the seed in double rows about 5cm (2in) deep and 13cm (9in) apart. If you are growing tall varieties use a strand of wire between two strong canes to support them. Use twigs or split canes on smaller varieties to keep the pods off the ground.

Extra water at the rate of 22 litres/sq m (5 gallons/sq yd) may be required in dry conditions, especially at flowering time; do not let the plants dry out. Feed with a low nitrogen feed, as the plants convert their own nitrogen; adding extra will cause lots of leaf growth and very little flower and fruit production. Hoe the rows regularly (but never in the wet as this can spread diseases from one plant to another). When about four sets of flowers have appeared, nip out the growing tip. This will allow all the nutrients to go into the beans, not the growing tip and it will help reduce any problems that may occur with blackfly.

Harvest dates will depend on the sowing time and the weather. As a general rule pick the pods while the beans are plump, but before the pod itself becomes leathery.

Beans are generally pest and disease free, but watch out for blackfly and mildew. Spray with a proprietary spray recommended for vegetables, following all the instructions given on the packet.

Climbing Beans (Runners)

Some varieties may grow over 3m (10ft) and some are naturally dwarf at around 35cm (13in). The flowers are red, pink, white or bicoloured, followed by flat pods, some over 25cm (l0in) long. The plants require a growing season of about 100 frost-free days. The ideal growing temperature is around 14-19°C (57-64°F). If the temperature is higher, especially if the humidity is high as well, the flowers may not set fruit well. Planting in light shade helps, especially if hot, humid summers are the norm in your area. Runner beans are deep-rooted and need moist, fertile soil to perform well, so prepare the soil well by digging a trench about a spade deep and 60cm (24in) wide. Dig in lots of well rotted garden compost or peat.

Sowing the Seed

Before sowing the seed, set up a method of support. There are various methods, try one made of strong poles or canes, over 2.5m (8ft) long, crossed over and tied at the top with a horizontal cane or together as a wigwam. Some people use square netting (not plastic-coated as the beans can't cling to it) fixed to a pole frame, or allow the beans to twist up strings fixed to a frame. Whichever method you choose, do it before you sow the beans.

Plant the beans in situ, 5cm (2in) deep in double rows about 60cm (2ft) apart, or about 15cm (6in) apart if using the wigwam method. Sow as soon as all risk of frost has passed and the soil has had a chance to warm up a little; the end of April or the beginning of May is generally fine. Poor germination is often caused by the seed being planted out too early into cold and wet soil. In colder areas, sow the seed indoors in seed trays, keep them cool, as one of the biggest causes of non or poor germination is due to the seed being started off in hot greenhouses. Harden them off and plant out as soon as possible.

After planting, mulch well to retain soil moisture. As runner beans are frost-tender protect the seedlings with cloches or floating mulches; do not let the plants dry out. Extra water at the rate of 5-11 litres/sq m (1-2 gallons/sq yd) twice a week may be required, especially in dry conditions and at flowering time. Feed with a low nitrogen liquid feed every 10-14 days, as the plants convert their own nitrogen, adding extra will cause lots of leaf growth and very little flower and fruit production.

Harvest dates will depend on the sowing time and the weather. As a general rule, pick the pods when they are at least 17cm (7in) long and tender. Keep picking the beans as this will prolong the cropping time of the plants.

Beans are generally pest and disease free, but watch out for blackfly and mildew. Spray with a proprietary spray recommended for vegetables, following all the instructions given on the packet.

French/Dwarf Beans

French bean growth is similar to that of runner beans. The pod sizes range from thin, pencil like beans to about 2cm (¾in) in diameter. They are round, flat or curved in shape and come in a range of colours from green, yellow, red or purple, there are even green beans flecked with purple.

The ideal growing temperature is around 16-30°C (61-86°F). The seedlings will tolerate a temperature of no lower than 10°C (50°F). (NOTE: never eat the pods or beans raw. They contain toxins which are destroyed by cooking).

Sowing the Seed

Sow the seed in situ 5cm (2in) deep and 15cm (6in) apart, as for runner beans grow on a wigwam, or alternatively sow individually in 7.5 cm (3in) pots about six weeks before the last expected frost. French bean seeds require a minimum temperature of 12°C (54°F) to germinate, so bear this in mind when sowing outside. Poor germination is often caused by the seed being planted out too early into cold and wet soil. Keep the young plants grown indoors cool and transplant out as soon as possible. One of the biggest causes of non or poor germination is due to the seed being started off in a hot greenhouse. Incorporating very well rotted manure and using black plastic over the bed in the winter will help warm the soil so sowing direct is possible. Seeds sown direct in warmed soil tend to catch up with the young plants very quickly, so direct sowing is preferred and generally less costly and time consuming. Use the same type of supports given for runner beans, or for shorter growing varieties use twigs or short canes, do not let the plants dry out. Extra water at the rate of 22 litres/sq m (5 gallons/sq yd) may be required, especially in dry conditions and at flowering time. Feed with a low nitrogen liquid feed every 10-14 days, as the plants convert their own nitrogen; adding extra will cause lots of leaf growth and very little flower and fruit production.

Harvest dates will depend on the sowing time and the weather. As a general rule pick the pods when they are young and tender. Keep picking the beans as this will prolong the cropping time of the plants.

Beans are generally pest and disease free, but watch out for blackfiy and mildew. Spray with a proprietary spray recommended for vegetables, following all the instructions given on the packet.