Site and soil | Varieties | Sowing | Aftercare | Picking | Pests and Diseases
French beans, or les haricot verts as the French call them, are one of the most popular garden vegetables, flavoursome and versatile in cookery, and they are very easy to grow. They need no thinning, transplanting or training as other vegetables do. They are quick to give results, they are very prolific, and freeze very well.
Site and soil
Choose a warm sunny spot for french beans so that the air temperature will be as high as possible. Shelter is important and a sun trap can increase temperatures by a couple of degrees. The plants also need shelter from strong winds that can topple the plants when wet of when carrying a heavy crop. But the shelter must not cast shade because they need full sunshine for rapid growth. French beans must be grown in fertile open soil. Being members of the legume family, they have nitrogen-fixing bacteria in their root nodules and these need lots of air in the soil, so the structure must be loose and open. Fairly light soil to which plenty of organic material has been added would be ideal.
There are two kinds of french bean varieties, bush beans and climbing beans. The bush types are most common and less trouble - no need for canes or other support. Most of the varieties now offered are ‘stringless', that is with no strong ‘string' running down the back of the bean. Bush types take about sixty days to mature pods, less for some early kinds in good weather, more for the slower kinds and in cool weather.
‘The Prince' is a standard variety with long slim pods that are oval in section. It crops well and reliably, and over a long period if the beans are picked regularly and it is good for freezing. ‘Sprite' is another good variety with round pods, completely stringless. ‘Tendergreen' is round and a good cropper, early to mature, and good for freezing. ‘Masterpiece' is another early maturing variety, with long flat pods and a good cropper. ‘Safari' is a Kenyan type, carrying slender, round bean pods that used to be called ‘filet' beans. ‘Delinel' is a good cropper, also a filet type of good flavour. ‘Opera' is an early maturing type of filet or Kenyan bean. A new variety ‘Speedy' is reputed to be very quick to mature. There are varieties with coloured pods, such as ‘Purple Queen' and ‘Orinoco', a yellow pod variety, but these are mostly of novelty value, the purple colour goes in cooking.
The climbing types are not as much grown. They are somewhat slower to mature, having to make a taller plant and the beans are generally more robust but still much finer than runner beans. Being capable of self-pollination without visiting bees, climbing french beans fare out better in a dull summer. ‘Cobra' is a standard climbing variety, stringless, round pods and continuous cropping. ‘Rustico' is early maturing and has slender round pods.
French beans are originally from Mexico and Central America and as a result they need warmth in the soil to germinate. They can be sown in April and May in good warm weather, but it is best to wait until conditions are right because they often fail or result in a patchy row. Seeds can be sown in pots in a greenhouse in April for planting out in May and this can be a first crop. They can also be sown to mature in the greenhouse or under the protection of cloches, cold frame or fleece.
Sowing is normally done in rows about 40 or 50cm apart, the beans spaced about 5cm apart in the row. This spacing covers some losses and gives a nice dense row of bean plants that keeps weeds down. Repeat sowings can be made at intervals of two to four weeks until July, depending on need, to keep a supply going.
French beans need relatively little care after sowing, making them a very easy vegetable to grow. The main concern is to control weeds by careful hoeing as soon as the bean plants appear above the soil. The climbing sorts need support with canes or sticks of some sort and may need to be encouraged to climb. If the garden is very windy, even bush beans may need a few bushy twigs to keep them steady. The plants are very fast-growing and if a dry spell comes, they should be watered.
French beans should be picked as soon as they are usable, even less than finger-length. These early beans are delicious and early and regular picking helps to keep the plants cropping. If there are too many to eat fresh, they can be frozen very successfully in batches. If there are enough stored, the late beans can be left to ripen on the plant and used as haricot beans, or used as seed the following year, as they come true to type.
Pests and diseases
Slugs and snails can wreak severe damage on the emerging beans and for a time afterwards. Black bean greenflies can attack foliage and pods. Root rot disease can occur in wet years and on heavy soil. Leaf spot diseases can occur but are unusual, as they are carried on the seeds.