The Yacon, which is also known as the Peruvian Ground Apple is related to the sunflower, in the Astereceae family and the Jerusalem artichoke. It originates and is grown in the northern to central Andes from Colombia to northern Argentina and has crisp and sweet tasting tubers. They are now becoming more readily available for the home gardener too.
Yacon plants can grow to over 2 m in height, producing small, yellow flower at the end of the growing season and when grown as a perennial can give large quantities of the edible tubers.
In Sydney, a temperate region, they can be planted in October and November.
Growth habits and planting needs
Select a site that gets good sunshine and is protected from heavy winds.
Yacon need deep rich, friable soil that is well drained, so prepare the beds thoroughly by digging over well to a depth of 60 cm removing any stones or large clods. Six weeks before planting dig through well rotted compost and aged manure.
When ready to plant the rhizomes dig over the soil again adding some more well rotted compost and plant the rhizomes to a depth of 10cm. They can be started out in pots and then planted out when the rhizomes start to sprout. Mulch well with sugarcane mulch to suppress weeds while developing. Once the the plant grows the leaf cover will do this naturally.
The yacon grows rapidly in spring so give it plenty of space to grow with at least 60-80cm between plants or 100cm if you have the space.
Yacon like plentiful water and a soil that drains well. The soil should be sightly acidic with a pH of a 6.0-6.5.
If the tubers start to protrude from the soil hill up soil to cover and so prevent any damage to the rhizomes.
Yacon will take about 6 months to mature. The tubers can weigh 300g or even larger.
After the yacon flowers, the tops will begin to die and the tubers will be ready to harvest when the plant has fully died down. If the plant has been growing in deep rich soil a good number of tubers will have grown.
Gently loosen the soil around the plant and carefully lift the rhizomes and the tubers. It is also possible to remove some of the tubers with the plant in place. The tubers should not be left in the ground too long and in Sydney, are usually harvested around May.
Remove the tubers and leave out in a sunny place for a few days to help develop sweetness and then store in a cool dry place for a month to allow the sugars in the tubers to further develop. If the tubers are damaged use them sooner as they will not keep.
Store the rhizomes in coir or better still in pots of potting mix to plant out in late spring. leave some immature tubers with the rhizomes when storing in this way.
If you live in a frost free area then the rhizomes can also be left in the ground by careful harvesting. In this way the plant is grown as a perennial.
Prepare the tubers by peeling them then chop and sprinkle with lemon and use in salads. They provide a sweet crispness not unlike apples or water chestnuts and are rich in potassium. As the yacon oxidizes always toss in lemon juice to prevent discoloration when preparing for salads and fruit salads
In South America yacon is often used in fruit salad or salpicón de frutas to add a sweet crunch. Chopped yacon is added to pineapple pieces, chopped papaya and mango and tossed in freshly squeezed orange juice and a dash of lemon.
Yacon can also be stir fried, roasted or baked.
You can try out the amazing recipes that use yacon from Nichols Garden Nursery at: https://nicholsgardennursery.wordpress.com/category/yacon-recipes/