Edible Chinese Water Chestnuts

Water chestnuts are a glossy brown-skinned corm that is slightly flattened top and bottom similar to a gladiolus bulb. A corm is about 1 ½ to 2 inches diameter (4 -5 cm). The skin is removed easily and the crisp white inside is eaten. As part of the sedge family, it grows tall, 1 meter, reed like stems and is native to swampy areas in tropical Asia.

The edible water chestnut a common ingredient in Chinese cooking is quite different from the invasive water chestnut that is causing environmental damage in parts of the USA. Water chestnuts are the corm of a rushlike plant and the name is applied to several different plants, one being the Chinese water chestnut which is the subject of this article. Another form is the caltrop which takes a number of forms depending upon the number of bumps or horns it has.. These three are Tratra bicornis, Tratra bispinosa and Tratra Natans. The last with four horns was once known as the Jesuit’s nut and is an invasive pest in waterways of the USA The two-horned water chestnut can be poisonous if eaten raw. A third type is the arrowhead an edible vegetable that is a pale yellow colour.

Growers should seek good quality corms of the Eleocharis dulcis and check that they have the correct species. The various Tratra nuts are forbidden imports into Australia, their spikes can cause painful injuries to feet and are an aquatic menace.

During its long growing season each planted corm puts out lateral roots which develop more corms that send up shoots as new plants. It has been claimed that up to 100 corms can be produced from the original. Two and a half to three kilograms harvest per corm is possible.

Water chestnuts look like a chestnut with their bright brown skin and a papery outer skin and taste a little like one. Their crisp nutty flavour and texture makes them a delicious food to eat out of hand or cut up into salads. Otherwise, they are sliced and used in stir-fry cooking, their value being that they hold their texture well.

Chinese water chestnuts are packed full of nutrients and are an excellent food being particularly rich in the B vitamins. They are a good source of vitamin C and a moderate source of iron and potassium.

Water chestnuts are suitable to a permaculture because they can be part of a multi-cropping system. As the chestnuts are grown in a paddy, (a field flooded with water) which can be used for other crops when the corms have been harvested and the field drained. It will have residual fertiliser from the chestnut growing and be free of weeds as well as being wet, a perfect growing-medium for a following crop.

Many home gardeners use a small plastic lined pool or pond in which to grow their water chestnuts – the pond, besides being an interesting water feature is also an asset to an organic garden, as it tends to bring in small reptiles and frogs that help with insect pest management.

Some home gardeners have experimented with growing water chestnuts in children’s plastic wading pools. ( see Growing Water Chestnuts)

For most of us, the only available water chestnuts come in cans imported from Asia. Growing this nutritious vegetable and eating it fresh is a delight