Broad Beans

Fi Morgan, Bellingen Food Gardening, sourced from I Love Bello Shire, 29^th June 2021, with thanks.

Vicia faba is known as fava or faba bean. This bean is used as both a human and animal food, and as a green manure crop. “The broad bean plant is suited to regions of  >500 mm rainfall to achieve the seed size”.

Most beans grow best in the warm months. Broad beans are happily your winter bean. Broad bean seedlings are tolerant of frost but they don’t like warm weather. They stop flowering when the temperature gets to 30°C.  Other beans die at the hand of frost, or die down and hide until better weather returns. 

It is actually possible here to protect summer beans through winter from frost and cold air movements by judicious placement and creating a protective microclimate of other plants around them. This is for advanced gardeners. Mere mortals, read on.

Broadbeans

The end of winter and early spring tends to be a bit lean in the food garden. It’s the time when the cool season plants are finishing up and the warm season ones haven’t gotten going yet. It’s a good reason to have plenty of perennial plants who can be ready to pick from a lot sooner as they are already mature, or who are available all year round. And then there’s broad beans. These hearty, hardy beans are one of the earliest crops to mature to close that spring gap when there’s not a lot around. The leaves are edible as well as the beans, and as a legume they are good for your soil too by adding nitrogen.

If you think you don’t like broad beans, you may have been picking them when they are too old to be enjoyable. Don’t wait for them to be as large as possible! Small broad beans are succulent.  The time to pick beans for shelling is when the beans have begun to show through the pod and when the scar on the side of the bean is still white or green. When the scar is black you have left it too long. They are still edible but will be tough and mealy.

Pods up to about 5cm can be eaten whole. Larger than that the pod skin gets a bit tough so eat the individual beans inside. For older large beans, double podding is recommended for a lovely palatable bean. This means both removing the bean from the pod, lightly cooking for a few minutes, then also removing the outer skin on the bean by cutting a slit and popping the loosened inner bean out.

Enjoy them in risotto, in soup, as dip, cooked steamed or boiled and added to salads. They pair well with cheeses and salty foods. 

So how to grow them? 

It really does need to be said that these are hardy and almost bombproof plants. 

If you sow the seeds direct into your garden bed they will need protection from slugs who LOVE young broad beans. Some protection too for small newly transplanted seedlings is a good idea. I’ve found the cardboard inner of loo roll, chopped down to half height, works just perfectly around the base of each plant. 

Broad beans can grow to over a metre high and their stems are hollow and a bit weak. They tend to fold over. Stake and string around your plants. Grow them in a clump or rows two plants across. Put stakes on the outside and wind string around the entire planting at various heights. This advice comes from everyone!

They are rather prone to aphids. You do need to ‘do something’ about aphids such as squish or hose them off otherwise they take quite a toll on the amount of beans that grow.

Water broad beans regularly.

Maximise the beans

The detail that follows is about getting more beans per plant. Keep in mind that broad beans are one of those vegetables where you can reliably plant and get a harvest. The following info is about diving into detail.

There’s a bit of debate about the best time to sow in this area for highest bean yields. 

Broad beans show a marked response to time of sowing, with crops sown ‘on time’ having an excellent chance of producing very high yields. However, crops sown earlier or later than ideal will have reduced yields. Too early means flowers die unpollinated. Too late means not as many branches for flowers to form on and therefore fewer potential beans.

These are the puzzle pieces:

• Ideally you are sowing when the soil temperature is at least 7°C for greatest seedling vigour  with 15 – 25°C the ideal soil temperature germination range.
• Broad beans take 16 to 20 weeks to reach maturity.
• Flowers will drop off before being pollinated if temperatures are below 10°C or the days are too short when flowering begins.
• Pollen creation is triggered by temperature, and pollination is required for beans (the fruit) to happen. Even if they are flowering, if it’s not warm enough they won’t have pollen. Broad beans need atmospheric temperatures of 15 – 18°C before they set viable pollen.  In this area, that happens sometime around September.
• Broad beans can be grown until daytime temperatures reach 30 degrees, at which point flower production stops.  That means no more beans. If it’s too hot the flowers fall off before beans are able to form.
• They flower over 5 – 10 weeks, with only 10 – 20% of flowers producing bean pods.

Backyard growers here who I checked with, will sow anywhere between March and June. There was a preference for later sowing. This is because the bean plants tend to sit about doing nothing all winter just growing leaves, and then suddenly start making beans in late September – October when it’s warm enough for pollen production. Broad beans take up a fair amount of space in the garden and no one seems fond of these big plants doing f-all for many months, which is why they tend to be left until later. But! According to Paul of Barefoot Fruit & Veg, you want broad beans to have completely finished all their vegetive growth (leaves and stalks) before they begin flowering, to get the most beans per plant. For this to happen, he says they actually need to be planted waaaaay back in… February and for them to be waist high at least by June. According to my assembly of the puzzle pieces, broad beans should probably go in the ground sometime in April or May so they are fully grown and just starting to flower when the temperatures are suitable for pollen production. Pete Bufo has a local planting guide – he recommends May.

In any case, when they are about waist high, it’s time to side dress them with compost and rock dust, and to pinch off their growing tips so they form lots of side branches and therefore more places per plant for growing beans.

Planting

Plant about 5cm, and even up to 8cm deep when direct seeding.  Plants should be spaced about 15cm – 20cm apart, which is quite close for such a large plant. They are fine to plant either direct into the ground or in punnets and transplant.

From a professional propagator: “I soak mine for a short period no more than a couple of hours and when planted they need watering but thereafter the bean will do the rest unaided…. If you water them they have a tendency to rot off.”  Unless the soil gets hot and dries out, don’t water again after planting until they have sprouted as the beans can easily rot if too wet. Don’t worry if you forget to pre-soak the beans before planting. Most will still grow.

To optimise germination, I found that those planted SCAR DOWN were by far the best with 100% germination and not only that they were better plants. Those planted on their side were a way behind them and those sown scar up were absolutely hopeless. This goes for all beans. Scar down puts the seed in the best position for the first root to grow straight down and the new shoot upwards without them needing to do any twisting or turning to get into the right directions.

Broad beans take 8 – 14 days to germinate, and are ready to plant out 2 – 4 weeks after sprouting, when they have at least one pair of adult leaves

Plant them in full sun in well drained (though they tolerate a bit of waterlogging) loam to clay soil with a pH in the range of  7 to 9 (alkaline). They will not grow as well in light or acidic soils.

Acid soils (like ours) may not have enough available molybdenum and this should be added at planting. It’s needed by broad beans to process nitrogen. They also appreciate a feed of phosphorus and zinc.  So, seaweed and rotted manure or bone meal are a solution. Research has shown they do not need nitrogen added (as they make their own), so skip the chook manure. It just promotes an excess of leaves and has no effect on the number of pods.

Broad beans are predominantly self-pollinating, with some cross pollination as well.  Bees help but aren’t essential. The bottom pods will mature first and turn black, as will the bottom leaves. This will continue gradually upwards as the plant completes its life cycle.

In my experience you’ll be picking dried pods for seed saving from October. The first pods to form, which will be the lowest on the plant, are the best ones for seed saving. When plants are done DON’T pull them out by the root. That’s where the nitrogen nodes are. Chop, drop, turn into the soil as an in-place fertiliser.

If your plants get rust in wetter times, a feed of magnesium (epsom salts) followed four days later by molasses is said to be what they need.

For more great plant articles and gorgeous pictures please go to Fi Morgan’s website – https://www.wherefishsing.com/