Not all dwarf beans are French beans, and neither are all French beans dwarf. There are climbing varieties of French beans which can be grown in the same manner as Runner beans. There are also varieties of dwarf beans which are not French beans. Here, we talk specifically of French Beans. They are also known as Haricot Verts in some countries. (In French language, this translates to green beans.) Haricot Verts are NOT the same as Haricot beans. The latter are used only as dried beans.
We will simply call them all French beans. Incidentally, French beans originated in America, not France!
French beans are normally picked young and around just 4in (10cms) long. This is the case whether they are the normal dwarf types, or the climbing types of French Beans.
The pods are normally rounded, and do not show the seeds swellings as is the case with runner beans.
French beans normally grow to just 12in (30cm) high, and are bushy in habit. The climbing varieties obviously need canes as with the runner beans.
French beans are best started by sowing in pots - either indoors or in a greenhouse. One per pot is fine - and allow for ten percent failure rate. The French bean seeds should be spread out an a few sheets of damp newspaper for up to twenty four hours - helping them to absorb moisture and swell. Then they can be panted into individual pots.
Warmth is absolutely vital in the early stages of French Bean growing - especially at sowing time. They have a reputation of being difficult to germinate - even in the greenhouse. Failure will almost certainly be due to cold and wet conditions. It is far better to delay sowing until the air and soil warms up. This is also the case with greenhouse sown individual pot units for if you try to grow them too early, you will have problems at planting time if there are any late frosts. In the event of cold spring weather, the new plants should be covered with horticultural fleece, cloches or simply newspaper as an emergency when frosts are likely.
If you sow the seed direct into the ground in spring, a depth of 1in or 25cm is suitable. They should be sown in rows 30cm apart. The seeds can be sown at 30cm spacing along and between the rows.
If pot grown, then plant out after any frosts at the same spacing.
They will not need support, but are happy to be grown between rows of cabbage plants for support. There is a mutual benefit in that the beans will enrich the soil with Nitrogen.
Harvest regularly as they are at their best when young and tender.
French beans are one of the most productive of all vegetables. They will grow well in containers, and to add to the ornamental effect, there are yellow and purple pod types.
Once the plants get to the maturity stage, there are rarely any problems. However, slugs and snails are partial to the young shoots as they emerge as young seedlings. Before that, mice can be a problem - stealing the seed. Wire netting along the row helps.
Tendergreen and Atlanta are good for the traditional green types. If purple appeals, try Purple Queen, and a contrast can be had with the golden yellow, Gold Dukat French Bean.
IMPORTANT - Do NOT plant the young dwarf bean plants out until
all frost is over, and make sure that you
harden them off gradually before planting out into the garden.