Page 19 - ALG Issue 4 2024

Growing Broad Beans
They can be sown either in autumn (from the end of September to early November – so the ideal sowing time when you receive this issue) or spring (from early March to end of April, depending on location and weather conditions).
They need a moisture retentive but free draining good quality soil.The plant is erect, from 60 to 150cm tall (2 to 5ft) and bears few branches.The stem and branches are crowded with short-petioled compound leaves.The pods are nearly erect in clusters in the axils of the leaves, and the seeds are large and irregularly flattened.The broad bean will not tolerate hot weather: it is grown in summer only in the cool parts of the temperate zone, and during the winter in the warmer parts. Unlike many other beans, it tolerates slight freezing.
Sow them in a single row about 4 inches (10cm) apart and about 2 inches deep. When sowing them in a double row, space the two rows 6 inches (15cm) apart – and at least 2 ft (60cm) from other crops.They can grow from 2 ft (60cm) for shorter varieties, to over 6 ft (18cm) for taller varieties. In a sheltered garden, shorter varieties shouldn’t need support or staking, but taller varieties will benefit from some support: usually pea and bean netting
over the crop, which is raised as it grows. They need plenty of moisture at the roots, particularly as the pods are setting and starting to swell and are self-fertile so will set on their own pollen – but need insects to aid pollination and give you a good set.
Pests
There are three main pests of broad beans:
a) Mice can eat the seeds in the row
before germination, particularly early spring sown when there’s not much else to eat.
b) Slugs and snails can eat the young shoots and find them a delicacy!
c) The main pest, however, is blackfly on the growing tips. Once the bulk of the crop has set, these tips can be taken off as a deterrent and, if clean, eaten once cooked. If you do get an invasion of blackfly, use your preferred method of insecticidal control.
Diseases
One main disease of broad beans is Botrytis fabae: the chocolate spot fungus, which can have a severe impact on yield. It is one of the worst diseases in beans, as it results in foliar damage, reduced photosynthesis, and reduced bean productivity.
The fungus switches from non-aggressive
growth to aggressive pathogenicity under the combination of increased temperature and humidity, which is worsened by low soil potassium and phosphorus content and
by the higher humidity caused by higher seeding rates.The non-aggressive phase is marked by small red-brown leaf lesions, and sometimes the same on stems and pods. Treatment is less effective than prevention. Early planting avoids the problematic combination of high temperature and humidity in late spring into early summer. Decreasing seeding rate or thinning after emergence is also effective. Foliar fungicide is effective. If fava beans flower during the heights of summer temperatures, there is an increased risk of this disease. If transplanted instead of direct seeded there is a lower risk of Botrytis fa bae outbreaks.
Varieties
There are many varieties of spring sown beans and fewer autumn sown.The seed houses are continually developing new varieties.
The three most popular autumn sown appear to be:The Sutton, which is a very compact variety and so good for windy and exposed places, reaching only 35 to 45cm high. De Minica, one of the earliest to crop, and Aquadulce Claudia – probably the most widely grown cultivar for autumn sowing. All mature in May/June, depending on the season.
For spring sown cultivars, you are spoilt for choice. Some of the more popular are: Bunyards Exhibition which are over 100 years old, so have stood the test of time! Also, Masterpiece green longpod, Robin Hood, and a newer one named Hylon, which is good for exhibiting.
“Eating Broad Beans could boost health and mental wellbeing.”
...a Cambridge scientist has said. Dr Nadia Mohd-Radzman says chemicals in the much-loved vegetable are linked to lasting improvements in mood and emotion.
The protein and iron rich seeds also contain high levels of levodopa (L-dopa), used to treat people with Parkinson’s disease. L-dopa has been shown to be very effective in treating the condition known
as anhedonia, essentially the inability to feel or experience pleasure. And she says that “with growing numbers of young people experiencing mental health problems, a healthy diet is going to be crucial in tackling this.”
Are broad beans the next wonder vegetable? Food for thought.
David Allison
Allotment and Leisure Gardener | Issue 4 2024 | 19
VEGETABLES