Janet Wade explains how to grow and eat sugar cane.
It would seem humankind has always had a sweet tooth. Sugar cane (Saccharum officinarum) is thought to have originated in New Guinea, where it was grown for chewing at least 10,000 years ago. From there it spread to Southeast Asia, China and India, and eventually to the sweet-toothed around the world. A process for turning sugar cane syrup into granulated sugar was developed in India more than 2000 years ago.
Today, most of the world’s sugar still comes from sugar cane. However, by the time the cane is shredded, crushed and cleaned with slaked lime; transported around the world to refineries, where it is further boiled, evaporated and spun in centrifuges to separate the sugar crystals – which are then dried and packaged into bags for sale – little of its original nutritional value remains.
The glycemic index (GI) of refined sugar is 64, while the GI of fresh sugar cane juice is half that (at around 30 to 40). Fresh juice contains antioxidants, fibre and nutrients, such as calcium, potassium, iron, manganese and phosphorus. Even so, sugar is sugar and sugar cane should still be eaten as an occasional treat.
Juice can be extracted from the stems of home-grown sugar cane by crushing them using a mangle or old printing press, but it is easier to do what people have been doing for the last 10,000 years. Trim the tough, woody outside off the stem with a sturdy knife, cut the white pulpy insides into pieces and chew it, spitting out the remaining pith when you have sucked out the last bit of the sweet, but not sickly, refreshing juice. The effort the chewing takes acts as a natural brake on overindulgence.
Sugar cane is ready for harvest in the autumn, one to two years after planting. The canes become tough and yellow when they are ready to cut. The bottom of the stem contains the greatest concentration of sugar, so the canes should be sliced off as close to the ground as possible. The plant will regrow the following season.
It is best to use sugar cane fresh, but it can be stored in the refrigerator for two weeks or frozen for a couple of months. Thoroughly wash and dry the canes first and cut them into manageable lengths.
Sugar cane plants are available from garden centres in the summer, but, if you know someone who has a plant, they are remarkably easy to propagate. Cut a section of stem with up to six nodes and bury it horizontally in a shallow trench in the garden. Keep the soil moist (but not waterlogged) until it sprouts. You can also cut the canes into smaller sections around a single node and plant them, again horizontally, with the buds facing upwards, into seed trays or pots. New canes should sprout in two to three weeks in warm weather.
Sugar cane thrives in the warm temperatures and high humidity of our subtropical regions. It grows best in a rich, well-drained soil, in full sun, with plenty of water during the growing season. Given its preferred conditions, the clumps grow quickly to 3-8m tall, with stems 2.5-7cm thick, which double in number each season. The plants will tolerate light frosts and a range of less-than-perfect growing conditions, but the canes will be slower growing, shorter and produce less juice.
The clumps crop for three to five years before they lose vigour and need to be replaced. Avoid planting sugar cane too close to paths since the leaves have sharp edges.
Apart from deserving a place in the edible garden or food forest, sugar cane also merits a place in the ornamental garden. Its long, graceful leaves growing from shiny purple or bronze canes give it a resemblance to bamboo. Its wind tolerance makes it a good choice for providing shelter to other plants. While bamboo and sugar cane are members of the same family (the grass family or Poaceae), sugar cane doesn’t have the invasive properties of bamboo.
