French or dwarf beans (also called green beans) are often quite expensive in the shops, but as they frequently are imported, that's not surprising.
1. Growing, protecting and support
2. Which variety to grow?
1. Growing and protecting
Fortunately French/dwarf beans (Phaseolus vulgaris) are easy to grow as they don't need complications of canes or string - the only things to think about is frosts, since the cold will kill them, and slugs and snails. To overcome both problems, it's best to start off the seed in pots. This way you can sow the seeds indoors safe from the cold and pests; then once the seedlings are sturdy and night temperatures become safe, you can plant them outside. Or buy plug plants or slightly larger plants to put into the ground. Then either use your favourite slug remedy, or patrol on damp nights to hand pick the slimy so-and-so's.
As with most veg, beans do best in well-drained fertile soils in open, not shaded, sites that are sheltered from strong winds. In dry spells, remember to water, especially at flowering time. Being insect pollinated, make sure they can get to the flowers too.
Harvest around 6+ weeks after sowing - sow from April onwards at 10-20 day intervals to ensure a succession over the summer. Also pick young pods regularly to extend the cropping period.
Can be frozen to store. Should be cooked before eating. Perfect as a vegetable dish, or added warm to salads, for steaming, stir frying.
Spacing and bird protection
We like to soak our beans first for 12-24 hours in some water – just to check they are all likely to germinate.
Then sow either in pots for later transplanting outdoors after the last frosts, or later on directly into the ground.
Indoors, sow the bean seeds 5cm (2") deep in 7.5cm (3") pots or trays of seed compost. They should germinate in about a week if the temperature is warm enough (need minimum of 12 degrees C). Ater germination, a cooler environment is better, but protect from frosts. They need hardening off over about a week before planting outside.
Sow outdoors once the soil is warm, with two seeds together, 5cm (2") deep and 23cm (9") apart. Space rows about 45cm (18") apart. Water the drills well, and cover with about 5cm (3/4 in) of soil, and firm this with the flat edge of a rake.
Pigeons will enjoy hoovering up the beans as soon as you sow them, so cover the ground with garden fleece to foil them. This also keeps birds off the young plants, and provides some protection from cold winds and low night temperatures early in the year.