Resembling a sweet potato, Yacon (Smallanthus sonchifolius) is sometimes referred to as ‘the Peruvian ground apple’, an apt name for this crisp, sweet, underground tuber that can be eaten raw like an apple. This ancient-looking plant from the Asteraceae family, originated in South America and is grown for its sweet edible tubers which were known to be valued and cultivated by the Incas and are a staple in the diet of South Americans today.
I first started growing Yacon about fifteen years ago by planting a small rhizome bought from an online nursery. I instantly fell in love with this amazing plant after tasting the tubers from that first long awaited harvest. Since then I always grow some each year both in my own garden at home and my garden at work; where I love introducing new food gardeners to Yacon’s tasty tubers.
Yacon is an impressive plant, growing up to 2m in height with large arrow shaped furry leaves and small yellow daisy flowers which are produced in autumn. It is relatively easy to grow and can be grown in most mainland areas of Australia. Around the base of the stem of a Yacon plant, clusters of small rhizomes are produced which are very different in appearance to the larger edible tubers which form below.
These rhizomes can be divided and planted out mid to late spring after the last chance of frost or when they start to sprout. Each plant produces many rhizomes, so there are always plenty of extras to share with other gardeners; once you have a Yacon rhizome you’ll never need to buy more. Plant rhizomes, containing a few growing sprouts, about a 70-100cm apart, a few centimetres below the surface, into deeply cultivated soil enriched with plenty of compost and manure. Yacon requires a long growing season and will take 6-7 months to reach maturity (after flowering). Water regularly and consistently as sudden changes in moisture levels can cause the tubers to split.
Harvest Yacon after the foliage dies back in winter after flowering, by carefully loosening the soil around the plant before easing the entire root system out of the ground.
The edible tubers can then be snapped off from around the crown and the rhizomes kept and divided for a new crop. The edible tubers can grow up to 30cm long and weigh as much as 1.5kg. It’s not unusual to get twenty or more tubers from one plant. Allow them to dry in the sun and store in a dark cupboard for a week to sweeten further. Don’t wash them, but just brush the excess soil off before storing, they will keep for a few months.
Yacon has an interesting apple-carrot flavour with a texture similar to nashi pears. Tubers can be peeled and eaten raw, boiled or baked. The skin needs to be peeled off before eating as it can be a bit bitter. Once peeled the flesh discolours quickly so sprinkle it with a little lemon juice to prevent this and peel just before needing to add it to a meal. I love eating it just as I would an apple or pear, but it is also amazing cooked in a stir fry where it retains its crunchy texture and absorbs the flavours of the other ingredients. You’ll find many yummy recipe ideas online. Interestingly the main stem of the plant can also be eaten; it’s eaten like celery when young and traditionally the leaves were used to wrap other food during cooking.
Despite its sweet taste, Yacon has a low kilojoule content and is high in fibre. It contains high levels of inulin, a form of sugar that is hard to metabolise making it a popular choice for diabetics. Inulin also aids digestion and promotes the growth of beneficial bacteria in the intestine. Yacon is a good source of antioxidants, contains a great balance of 20 amino acids and is high in potassium, calcium, magnesium, phosphorus and iron. What more reasons do you need to give this amazing vegetable a go!