The winged bean is a legume whose young pods are a common vegetable sold in Singapore wet markets. The young tender pods are often stir fried with spicy prawn paste (sambal). Sambal kacang botoh (the Malay name of this dish) happens to be one of my favourite vegetable dishes too. This is a reason why I grow this legume as well.
Growing the winged bean in one’s garden to gather fresh, tender pods from the garden that can be picked at the stage which one prefers. Those sold at the wet markets can sometimes be too fibrous. The winged bean is rich in protein.
The young, tender fruits of the winged bean.
The Winged bean is botanically known as Psophocarpus tetragonolobus. The specific name tells us something about how the pods look like - the presence of four frilly ’wings’ that run lengthwise along the pod. The Chinese here call it the ‘four angled bean’ as a result.
This legume, unfortunately, is a sprawling, large growing vine. It needs to grow to a large size (several meters) before it flowers and sets fruit. It is therefore better grown outdoors in a community garden with a large, strong trellis for it to climb. It is hence not suited for pot culture in an apartment garden.
Look at how large and dense a winged bean vine can get!
The winged bean vine can continue to grow for quite a long time and appears to be a perennial in the tropics. Once it starts fruiting, it will produce pods almost continuously. The flowers of the winged bean is quite decorative, in my opinion. They are a light bluish violet in colour – a rare floral colour in the tropics!
The blue flowers of the winged bean.
The seeds of the winged bean seems to be a little difficult to get locally. The best source is to ask for some fresh seeds from a fellow gardener who is growing the vine. I find that the seeds of the winged bean tend to have problems germinating after they have been stored for some time. Because the seed coat is rather thick, the seeds should be soaked in water overnight to promote germination.