Even if you don’t have a designated vegetable patch, you really should try growing green beans.
Not only is it relatively easy to get a satisfyingly good crop, but they can also be trained to grow up a variety of different decorative structures providing a lovely centrepiece for even the most bijoux of courtyard spaces.
Their pretty flowers, which, depending on the varietal can range from dark blue, through purple and lilac to white, put on a lovely display as well as producing a healthy addition to your dinner table.
Nasturtiums are a good planting companion to repel bean beetles and their yellow/orange/red colours contrast beautifully around the base of the beans if you have a white flowered variety.
Central and South America
Optimum pH 6.0-7.5
Green beans, also known as dwarf beans, snap beans, French beans and bush beans, are one of the most profitable crops for the home gardener. They can be closely spaced where only a few rows are involved and yield heavily in relation to the area they occupy.
Green beans are tender, and even where temperatures do not reach freezing point the growth is always poor and uneven and the pods tough and misshapen. In spring and summer, however, they mature quickly enough (7-10 weeks) to satisfy even the most impatient gardener.
There are many cultivars, but recent years have seen a definite preference for the round-podded, stringless type.
Flat-pod cultivars have all but disappeared from seedsmen’s catalogues.
Contender: An outstanding stringless cultivar with buff-coloured seed.
Golden Wax Pod: This cultivar bears well and is reasonably stringless, even when the plants are past their prime.
Seminole: Produces heavy crops of dark green pods and has dark brown, speckled seed.
Top Crop: Similar in most respects to Seminole, even having seed of a similar colour.
Soil Preparation Before Growing Green Beans
Most soil will produce a satisfactory crop of green beans as long as it is loose and friable and provided that drainage is good. Heavy soils and those that crust easily should be avoided, for they interfere with germination and particularly with the emergence of the seedlings.
In such soils, unless they are kept uniformly moist until emergence is complete, the seeds may germinate but the young brittle stems find the task of pulling the fleshy cotyledons to the surface, beyond them.
Consequently a large percentage of the stems usually snap, resulting in a poor stand of plants.
Beans grow particularly well when they follow heavy feeders such as cabbages, cauliflowers or potatoes, for which the ground was generously improved. Frequently the residue of fertilizer and organic matter remaining in the soil after these crops have been removed will carry a quick-maturing crop such as this through to maturity.
However, to ensure that the necessary quick growth occurs, an application of 2:3:2 at the rate of 60 g per metre of row or per m2, depending upon the planting pattern, can be made. Quick growth is essential, and slow growth usually results in a low yield of tough and misshapen pods.
Propagation Of Green Beans
Beans are propagated by seed that is almost always sown where the plants are to mature.
The seed should be carefully examined before sowing to see that it is free from weevils and from the scars caused by halo blight. Shrivelled seed, too, should be avoided, and the hands should be washed well after sowing seed that has been treated.
Sowing of Green Bean Seeds
Seeds should be sown singly 75-100 mm apart in the row in holes made by a dibber against the planting line or in a drill opened up along the line. The depth of sowing must be carefully watched, particularly for early sowings, if an even stand of plants is to be obtained.
In light to medium soils, 40-50 mm is a reasonable depth, but in heavier soils 30-40 mm is sufficient. On heavy soils a more even stand will be obtained if the rows are given a temporary mulch of fine grass or lawn mowings, or if the drills are filled in with sand, loose soil or fine compost to prevent crusting.
In larger plantings, 400-450 mm should be allowed between rows. Alternatively, double rows 150 mm apart can be planted, with 450-500 mm between each set of rows. In intensive bed culture 300 mm between the rows will give higher yields if there are only 3 or 4 rows, without markedly reducing plant development.
As the harvest period of beans rarely exceeds 4 weeks it is essential for continuity of supply that sowings should be made every 3 weeks or so.
Further Treatment For Growing Green Beans
Owing to their short growing and harvest period beans require relatively little attention, and on clean ground 1 or 2 shallow cultivations should suffice from sowing to maturity.
Ground that has been well prepared usually contains sufficient nutrients to carry the plants through. However, if after 3 weeks or so growth is unsatisfactory a dressing of 2:3:2 at the rate of 30 g per m2 should improve growth and lengthen the picking period.
Watering should be carried out carefully, especially during the germination period and with early sowings before the soil warms up.
As with most plants, watering is extremely critical during the flowering and fruit setting period, and with beans a shortage once the pods have set will cause them to be small and stringy.
All beans are very shallow rooted, and under favourable growing conditions the lush top growth, particularly in wet weather and when the plants are heavy with pods, becomes a bit much for the stems to support. This makes the plant prone to damage by rain and wind.
Drawing a little soil up to the stems while there is still room to work with a hoe between the rows will assist the plants to withstand bad weather. A mulch with short material to a depth of 50 mm will also have a beneficial effect.
Harvesting Green Beans
The pods are usually ready for picking 7-10 weeks after sowing, depending upon the season and the cultivar grown. The pods should be removed while they are still young and tender and before any swelling of the seeds occurs.
In hot weather the plants should be cleared of pods twice a week, even if this means putting surplus quantities in the deep freeze.
If a few pods are allowed to become coarse and stringy, the picking of uniform pods is extremely difficult and the strain on the plants shortens the picking period appreciably.
As bean plants are very brittle, particularly at this stage in their development, and are easily damaged if pulled around roughly, the plant should be held with one hand while the pods are removed with the other.
Collecting & Growing Green Bean Seeds
If a row or two are to be kept for seed, dry beans or sprouts, all the pods should be left on the plant until they yellow and become dry. The plants can then be removed in their entirety and hung up in an airy shed or laid thinly on trays. When they are thoroughly dry the pods can be shelled and the beans stored.
Green Bean Pests
Cutworms are often a problem.
Drenching the young plants with carbaryl or dusting the soil with BHC usually effects control, as does cutworm bait broadcast along the rows.
The bean-stem fly occasionally causes trouble. Although it rarely kills plants outright it stunts growth, makes stands uneven and lowers yields. The adult flies, black in colour and extremely small, lay their eggs in the tissue of the lower leaves, usually near the leafstalk or petiole.
The larvae tunnel down the petiole and the main stem until they reach a point at or just above soil level, where they pupate in the outer stem tissue. In most instances a swelling develops, especially where several larvae are involved, and sometimes the pupae can be seen in slits on this swelling.
Malathion is, again, a suitable material for effective control.
Diseases Afflicting Green Beans
Diseases are usually only troublesome when there is wet and overcast weather with warm temperatures.
Anthracnose is a fungal disease causing browning and blackening of the veins on the underside of the leaves, angular spots on the upper surface, and reddish-brown or black sunken spots on the pods themselves.
It is common on ground that has carried several crops of beans within the space of a few years and its establishment is assisted by prolonged cool and wet weather.
Brown sunken spots appear on diseased seed and this is the major method of infection, although the disease can overwinter in diseased material left on the ground.
If possible, only certified seed should be used. Plants can be sprayed with Dithane M45 at 7-10 day intervals if necessary.
Brown rust is a common disease, especially during wet periods and on late sowings. It is recognized by the small brown pustules that mostly occur on the underside of the leaves, each pustule having a yellow halo.
Spraying with Dithane may arrest its development during dry spells.
Bacterial blight is a disease that has similar pod symptoms to anthracnose but it produces small water-soaked spots, like grease spots, with green or yellow halos, on the foliage.
Clean seed and crop rotation are the only methods of control, although the cultivar Seminole is said to have some degree of resistance to one of the bacteria responsible.