Yams are tasty and worth growing

Press, 15 October 1976, Page 8

Yams are tasty and worth growing

Yams are a delicious vegetable. Yet there are people who have never tried them, and many would not even recognise the tubers for what they were if they saw them. Of course, the yam, or oka as we know it in New Zealand, is but a member of the genus oxalis, Oxalis crenata. The true yam is a tropical plant, a vine which larger tubers than our locally fcrown product of the same common name. Yams are frost tender and require a long warm late summer and autumn not only to increase the yield but also to improve their flavour. If dug prematurely they may not keep well, the skins may blacken and the flavour may be somewhat acid. This latter aspect can usually be rectified if the tubers are left in the sun for a short while after digging. With regard to harvesting, the best method is to leave the plants until the frost blackens them. However, mild autumns

and similar early winters can mean a long wait before this eventuates, so digging any time after the end of May-early June is suggested. Digging requires considerable care because even the smallest tuber which is left behind will give rise to a young plant in the following spring — a feature well known (and not an endearing quality) to those who have grown yams in their garden. Tubers tend to vary somewhat in colour from very light pink to red. However, the colour does not seem to influence the flavour in any way.

Seed does not seem to be generally available and it would seem that the solution to this problem is to use tubers which are sold to be eaten.

Susceptibility to frost has already been mentioned and this precludes too early planting of the crop. The somewhat vague advice to plant "after the danger of frosts has passed’’ applies here and it is up to the discretion of the grower as to when ‘his can reasonably be applied. Planting depth and spacing is similar to that of potatoes, about 45cm between plants, 60 to 70cm between rows and 75 to 80mm deep. Fertiliser requirements are also much the same. A 6:2:1 mixture by weight of ammonium sulphate, superphosphate and potassium sulphate sprinkled down the row at the rate of 40g per metre of row can be taken as a general recommendation.