How to grow yacon
Overview
Yacon (Smallanthus sonchifolius) is a perennial vegetable grown for its crisp, sweet tubers that taste like a cross between apple and watermelon. It is a member of the Asteraceae family and is prized for its low glycemic index. Gardeners should know that yacon requires a long, frost-free growing season of 6–7 months to produce a good harvest.
Varieties
- Yacon — The standard variety grown in Australia, producing large, sweet tubers.
Soil Preparation
Yacon prefers loose, well-drained soil rich in organic matter. Ideal pH is 5.5–7.0. Incorporate compost or well-rotted manure before planting to improve fertility and drainage.
Growing Guide
Plant yacon in full sun in well-drained soil. Space plants 60–80 cm apart in rows 1 m apart. Plant tubers or crowns 5–10 cm deep after the last frost. Water regularly to keep soil evenly moist, especially during tuber formation. Hill soil around the stems as they grow to support the developing tubers and improve yield.
Care
Feed yacon with a balanced fertiliser (e.g., 10-10-10) at planting and again in midsummer. Avoid high nitrogen fertilisers, which promote foliage over tubers. Remove flower stalks to direct energy to tuber growth.
Companion Planting
Yacon grows well with corn, beans, and squash, which provide shade and support. Avoid planting near potatoes or other root crops that compete for space and nutrients. Marigolds can help deter nematodes.
Common Pests & Risks
Slugs and snails can damage young shoots and tubers; use organic baits or traps. Rodents may also chew on tubers; protect with wire mesh or traps. Aphids occasionally attack new growth; control with insecticidal soap or neem oil.
Harvesting
Harvest yacon after the foliage dies back in late autumn or early winter. Carefully dig up the clump and separate the tubers from the crown. Tubers can be stored in a cool, dark place for several months.
In the Kitchen
Yacon tubers can be eaten raw, sliced into salads, or juiced. They have a crisp texture and sweet flavour. Store tubers in a cool, dark place for up to several months; they become sweeter after a few weeks of storage.
Troubleshooting
Yellow leaves: overwatering or poor drainage; reduce watering and improve soil drainage. Stunted growth: lack of nutrients or water; apply balanced fertiliser and water regularly. Tubers small or few: insufficient sunlight or overcrowding; ensure full sun and proper spacing. Leaf spots: fungal disease; improve air circulation and avoid overhead watering. Rodent damage: protect tubers with wire mesh or traps.