Growing Yacon in Southern Victoria, Australia
Posted on March 23, 2016
Although yacon is a perennial in tropical climates where it will grow all year round, it is grown as an annual here in Victoria where it is cooler. It will die down after frosts in early winter, which is when you harvest the large, sweet and crunchy tubers. Unlike many ‘new’ foods, the taste is pleasant to most people at their first taste. Generally people describe the taste as a cross between watermelon and apple but not as sweet, and with a water chestnut-like texture. It is juicy, crunchy and smooth on the palate.
Before we go any further, I live in a Mediterranean climate where we don’t get serious frosts or freezes. I don’t have experience in very cold areas but as long as the plants get 6-7 months of growing time you will be ok.
Yacon grows well where the climate is mild and in areas with a long growing season. It can be grown as a perennial in warm areas, harvested on demand, or grown as an annual in cool areas, harvesting in the winter.
It will grow and produce well in either dappled or light shade, especially if summers are very hot, or grown in full sun as long as water is kept up to them in very hot weather. I grow them in both positions with no trouble. The plants grow best with fertilisation and a good, loamy to sandy soil but should never be waterlogged. Dig in some well rotted manure well before planting in spring and they shouldn’t need any more feeding until harvest. I plant the growing tubers straight after harvest in their new beds and they will start growing in spring when they are ready, or you can store them in dryish soil in a pot till you are ready to plant them in spring.
If your soil is heavy, it would probably be best to grow them in raised beds, not only for them to produce the best tubers but also so you do less damage while harvesting.
Propagation roots with pink or purple growing points can be planted in a well-dug bed in early spring, near the time of the last expected frost. While aerial parts are damaged by frost, the roots are not harmed unless they freeze solid. Yacon is a vigorous grower much like Jerusalem artichokes, but doesn’t spread like them.
Yacon growing tuber/set
If you don’t have as many growing tubers as you would like, yacon is very easy to root from stem cuttings. Just wait till it is growing vigorously and take cuttings around 15cm or so from the stems. They root with no problem, even if you just push them in the ground where you want them to grow.
After the first few frosts in autumn or winter the tops will die and the plants are ready for harvest. It is generally best to leave some in the ground for propagating the following spring. Alternatively, the propagating roots can be kept in a bucket of damp wood shavings or buried away from frost until spring. While some usable-sized tubers develop fairly early in the autumn, they taste much sweeter after some frost
Yacon actually produces two types of underground tubers, reddish rhizomes with pinkish growing tips directly at the base of the stem, which can be eaten when young but are mainly used for propagation and the larger brown tubers, which are eaten as they don’t have eyes for regrowing.
Pink/purple growing sets and brown tubers for eating
When harvesting, separate the reddish rhizomes from the tubers and wash off any soil, taking care not to break the skin. Remember that the tubers are brittle so be careful with the fork. The reddish rhizomes are kept out of the sun in a dark, dry place, placed in a bucket or box and covered with slightly damp sand, sawdust or cocopeat to stop them drying out and put aside for replanting. Plant in good, loose soil with aged manure added.
After harvest, the eating tubers should be left in a tub or basket in the sun, or in the garage for a couple of weeks while they sweeten (they are not sweet when they are first taken out of the ground). When the skin is slightly soft they are ready for eating.
I like to peel them and chop into fingers to eat, either in salads or as it is. Yacon can also be baked where it will not go crisp but will stay crunchy and take on the flavours of what it is cooked with. You can also grate the peeled roots and squeeze out the juice which can then be boiled down to a sweet syrup.