Beans make up a range of plants that are generally easy to grow, produce good yields and can be stored easily, providing homegrown food across the year. There are a good number of varieties and they can be grown in many different locations and across the year. Eaten whole (including the pod or shell) they are generally very high in protein and versatile in the kitchen.
Within the UK there are 3 main varieties of beans grown in gardens and on allotments. French, runner and broad beans. It is possible to widen this to some other beans such as Edame beans and long beans but they may require some extra attention and care. Of the 3 main types broad beans are the more hardy and will tolerate frosts, whereas French and particularly runner beans require warmer temperatures and on the whole are not tolerant of frost.
All can be grown from seed either starting in pots or direct where they will crop. In cooler parts of the UK, starting in pots is likely to be necessary to provide a long enough growing season for the plants to mature and produce. When grown in pots it is best to find a relatively good, evenly lighted position for them because if they have to stretch for light, they will grow leggy. Root trainers or even kitchen role tubes can be good to sow into as it promotes good deep roots that the beans will need for anchorage as they grow taller.
Broad beans can be sown into position either late in the year for early crops (October to early December), or from February and March when the soil can first be worked, they germinate best in cooler conditions. Taller varieties will benefit by being supported with canes, particularly once they start to produce their pods and become heavier and more susceptible to being blown over by wind. They need to have their growing tips pinched out once in full flower. This helps develop the best quality beans and deters the likely black flies already earning a living on your plants.
French beans have the greatest variety of different cultivars, from dwarf to climbing and almost seedless to varieties grown for just their seed. Lots of other types of bean, we often find in tins and dried, are actually a variety of French bean, like butter, borlotti and pinto. In fact, even French beans is a more culinary descriptor than a biological or horticultural one. The latin and plant genus for the common bean (which French, runner and the others are part of) is Phaseolus vulgaris. But across seed packets, gardening books and plants you will find the name French bean.
The main difference you often find is between the dwarf variety and the climbing variety. The dwarf variety generally crops quicker and requires less structure, generally doesn't need any support, suitable for container growing. The climbing varieties will produce greater yields but require more space and planting depth. The majority of French beans are planted out or sown direct in late April or early may. Some varieties have been developed for a quality pod that can be eaten whole as a green bean. Other varieties have been developed for the seeds to be eaten or dried for storage. Green beans store well as a frozen food.
Runner beans are very British bean. It is crop we perhaps all enjoyed (or perhaps not) in childhood as it was very popular as a back garden or allotment crop. They require even warmer weather than French beans and are generally planted out or sown direct at the end of May and early June. In cooler parts of the UK, sowing indoors for planting in early June is essential to make the most of the shorter growing season.
Runner beans are also valued for their architectural quality, providing screening and shade when planted in the right location. Many an allotment takes a break in the shade of their runners in late July and August. Runner beans require the sturdiest of structures. Ensure the canes are well footed into the soil and use string to provide strength. Eventually the weight of each plant will become substantial. Generally planting or sowing 2 seeds per cane will give enough space and enable the structure to hold.
You can also train runner beans into a dwarf bush, nip of the growing tip when they are around 20cm to 30cm high and then nip off the subsequent side shoots at the 2nd joint. This produces a good bush shape that will produce a satisfying yield. The main difficulty with runner beans is ensuring pollination is set. There are lots of ideas on the internet to encourage setting of the pods but in general the most reliable approach is ensuring they have plenty of watering once they begin to flower.
Beans in general need watering/good moisture level from the time they set flowers through to their cropping period to ensure you get quality pods and reduce toughness. If we haven’t had a good rainfall, water well twice a week. All beans are susceptible to wind damage so a sheltered position is best (if your garden is windy then dwarf varieties will do better). They all prefer good nutritious soils, with organic matter being added the winter before, and good sunlight.