French beans,sometimes called dwarf beans, are often grown as an alternative to the coarser runner bean.
They are drought tolerant,and like other legumes,they return nitrogen back into the soil through rhizobium bacteria nodules on their roots (white lumps clustered around the roots).
They are easy to grow, and unlike runner beans, they do not need staking, unless they are a climbing variety.
They don't crop for as long as runners they should be sown in batches every few weeks, and crop best on light, well drained slightly alkaline soil.
Depending upon variety, the pods are either flat, or pencil podded, and mature from July to October subject to sowing times.
They are at their best if the pods are picked and eaten when they are young and tender.
If they are left too long on the plants they become stringy and the plants stop producing.
Beans ready for harvesting
Dwarf varieties grow to 250-300mm (10"-12") high and are generally self supporting, whereas climbing varieties, may grow to 2metres (7ft) tall, and require supporting.
There are other varieties known as haricot beans, or flageolet beans, where only the dried seeds are eaten, not the whole pod.
Flageolets should be harvested when the beans are soft and green, and haricots when the seeds have ripened to white or light brown.
Make an early sowing outdoors under cloches if ground conditions allow, keeping them covered until the end of May.
Alternatively sow 1 or 2 seeds vertically to a 75mm (3") pot., or sow into celltrays and place them in a frost free frame to grow on until planting out time.
Germination should take around a week if sown indoors or undercover, whereas outdoor sowings may take two weeks or more subject to conditions.
Week 17 - 19:
Prepare beds for main crop sowings, by raking in a top dressing of fish, blood and bone fertiliser at a rate of 80gms (3oz) per sq. metre.
Remove any weeds that have gown since initial preparation last October.
Never sow in soil that is wet and cold, and never pour water in the drill at sowing time.
Prick out seedlings that have been sown in boxes / trays into individual 70mm (3") pots.
Plant out potted seedlings 150-200mm (6"-8") apart providing all late frosts have passed*.
*Covering with cloches can offer some protection should a sudden sharp frost occur.
Seedlings Planted out
Make outdoor sowing by sowing the seeds 75-100mm (3"-4") apart in 50mm (2") deep drills.
When the young plants are showing the first pair of leaves, thin them out to 150-200mm (6"-8") apart.
Make successional sowings twice a month until Week 30.
Ensure that both dwarf and climbing varietes do not dry out particularly around flowering time as this could have an affect on the flowers setting.
Keep dwarf varieties weeded and provide support for climbing varieties.
Place cloches over the late sowings to protect the plants from early frosts.
French beans self-pollinate and seeds usually come true so it is worth while to save a few seed for next season.
Allow a few pods to mature on the plants until papery, then pick and leave to dry indoors.
When they are crisp, shell and store the beans in a cool, dry and dark place.
Prepare beds for next years crop.
French beans prefer light soil, but can be grown in heavy clay soil by digging the ground deeply, and incorporating copious amounts of well-rotted manure or compost.
Leave the ground rough during the Winter to let the cold winds and frosts get to it.
Generally speaking these varieties perform in a similar manner to the dwarf varieties but need some form of support as they can grow to around 2-2½metres (7-8ft) tall, .
Some of the more tender varieties (for example Cobra) are better suited to being grown undercover in say a greenhouse or tunnel, although in southern regions they will perform equally as well outdoors as most other varieties, for example 'Blue Lake'
Like their dwarf counterparts these too should be sown successionally over the season to extend their growing season.