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
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. al Asia.
The edible water chestnut (Eleocharis dulcis) which grows in dense thickets of tall (one metre) rushes and produces many new corms over the growing season which are eaten raw in salads or in Chinese type cookery. They are a glossy brown-skinned slightly flattened corm about the size of a golf ball.
With good growing conditions Chinese water chestnuts can be very productive. USA trials from the 1930s reported crops of about 50 Kilograms per hectare.
The growing season is 180 to 220 frost-free days although this can be shortened by pre-sprouting the corms.
The recommended method is to plant the corms about 5 – 8 cm deep and about 30 cm apart in the rows which are also 30 cm apart into a light sandy soil enriched with plenty of well-rotted manure. The soil is flooded and then when thoroughly soaked the water is run off.
The corms will sprout and when about 25 cm high the area is flooded again to a depth of 7 to 10 cm and this is maintained until the reeds turn yellow and begin to wither. The water is run off and the corms harvested after having been left for a few weeks so that the skins harden.
It is important that the water level is maintained at a steady level. If it rises and falls production will be compromised.
Do not over crowd – the harvest will be reduced.
In Australia, David and Nell Hoare reported that they grew their first, experimental crop by having a front-end loader operator carve out two small paddies. The dug out soil formed the banks. A load of sand was purchased and spread to a depth of 10 centimetres.
Cow manure was spread over this and mixed in. Corms were planted at 2 per square metre and the paddy flooded to 10 cm. 220 days later they let out the water and began harvesting. They reported excellent crops. It may have been better to allow the nuts to sprout prior to flooding.
Different authorities give planting depths that vary from 5 to 10 cm; similarly, the water level is given variously from 7 to 15 cm. Some maintain that the water is run in when the plants reach 10 cm and others 25 cm. The depths do not appear to be critical and a sensible average would appear to be reasonable.
In the back yard, almost any container can be used. Lage flat pots filled with enriched sand are quite suitable. Wading pools that are about 150 cm diameter have been used. Typically, these are about 25 cm deep. A sandy loam with well-rotted manure or compost is put in the pool together with a little dolomite to a depth of about 10 cm.
Plant no more than 4 corms spaced equally and soak the soil. When the reeds reach the height of the pool, top-up with water. The plants can have a top-up dose of fertiliser – liquid manure – about halfway through the growing season. Small fish can be introduced to restrict mosquitoes.
Some people have successfully planted straight into water in garden ponds. A large pond or dam can have a shallow ledge constructed and the corms planted there. However, the natural habitat of the Water chestnut is wetlands that dry out for part of the year. For best production this cycle should be followed.
It is not hard to grow – and no weeding during the growing season!