How to Grow Yacon Tubers: The Sweet, Giant Root from South America

Have you ever wished you could grow something unusual in your garden, something more exciting than potatoes, but just as easy to care for? If you’re like me, you’ve probably tried adding exotic plants here and there, but many don’t adapt well to U.S. climates. That’s where Yacon (Smallanthus sonchifolius) comes in. These giant, sweet Yacon tubers from South America not only thrives in many American gardens but also gives you crisp, juicy roots that taste like apples and watermelons combined.

I still remember the first time I dug up my yacon harvest. The tubers were so large I had to use both hands to lift them. And the taste? Like biting into a fresh pear straight from the soil.

In this guide, I’ll walk you through everything you need to know: where to buy yacon tubers, how to plant them, what conditions they need, how to harvest, and even why they’re prized for their prebiotic health properties. By the end, you’ll be ready to grow yacon in your own garden confidently.

What is Yacon (Smallanthus sonchifolius)?

Yacon (Smallanthus sonchifolius) is a perennial root crop originally from the Andes mountains of South America. Locals call it the “Peruvian ground apple” because of its crisp texture and refreshing, slightly sweet taste. It produces two types of underground structures: the edible storage tubers and the rhizomes (or crowns) used for replanting.

What makes yacon special is its high level of fructooligosaccharides (FOS)—a natural prebiotic fiber that supports gut health. Unlike other sweet tubers, the sugars in yacon don’t spike blood sugar levels, making it popular among health-conscious eaters.

People use it raw, roasted, or turned into yacon syrup, which is widely known as a low-calorie sweetener. But beyond the health angle, gardeners love it because the plant itself is beautiful—growing up to six feet tall with sunflower-like leaves.

Key Features:

• Botanical name: Smallanthus sonchifolius

• Plant type: Perennial tuber (grown as annual in cold climates)

• USDA zones: 7–10 (annual in colder zones)

• Height: 5–7 feet

• Harvest: 6–10 months after planting

• Flavor: Crisp, juicy, mildly sweet, like apple or watermelon

Unlike potatoes, yacon tubers are low in starch and rich in fructooligosaccharides (FOS), making them a popular prebiotic food and a natural sweetener when processed into yacon syrup.

Why Should You Grow Yacon?

There are plenty of reasons to give yacon a spot in your garden:

• High yields – One plant can produce up to 20 pounds of tubers.

• Adaptable to U.S. climates – With proper care, it grows well in most regions.

• Health benefits – Prebiotic fibers support gut health without spiking blood sugar.

• Unique taste – Adds a refreshing crunch to salads, stir-fries, or even raw snacking.

For me, the biggest reason was novelty. Friends would visit and ask, “What on earth is that plant?” Once they tasted the tubers, they wanted to grow it too.

How to Grow Yacon Successfully

Best Time to Plant

Plant yacon tubers or rhizomes after the last frost in spring. In warmer climates, you can start them earlier. Yacon needs a long growing season (6–10 months), so earlier planting means bigger harvests.

Choosing the Right Location

Yacon loves full sun but tolerates partial shade. Give it a spot with:

• At least 6 hours of sunlight daily

• Protection from strong winds (plants get tall)

• Room to spread (each plant can reach 3 feet wide)

Preparing the Soil

Yacon prefers loose, well-drained loam rich in organic matter. Think of soil where carrots and potatoes thrive. Heavy clay can cause misshapen tubers, so amend with compost or sand if needed.

Planting Yacon Tubers

Choose firm, plump pieces with at least one “eye” or sprout node. Avoid shriveled or soft tubers—they won’t produce strong plants.

1. Dig holes about 3–4 inches deep.

2. Place rhizomes horizontally with buds facing upward.

3. Space plants 2–3 feet apart.

4. Water thoroughly and mulch to conserve moisture.

Don’t worry if growth seems slow at first—yacon spends its early weeks building strong roots before shooting up tall stems.

Caring for Yacon Throughout the Seasons

Spring and Summer

• Watering: Keep soil evenly moist, especially during dry spells.

• Fertilization: Add balanced organic fertilizer mid-season. Too much nitrogen = more leaves, fewer tubers.

• Weeding & Mulching: Mulch heavily to suppress weeds and keep the soil cool.

Fall and Winter

As days shorten, yacon plants direct energy into tuber growth. Wait until the first light frost kills the foliage before harvesting. If winters are mild in your area, you can overwinter crowns in the ground. In colder climates, dig and store crowns indoors for replanting next year.

Common Problems and Solutions

• No tubers? Probably too much nitrogen or insufficient growing season.

• Yellow leaves? Check drainage—waterlogged soil causes root rot.

• Pests? Rare, but aphids or nematodes may appear. Use organic controls if needed.

Harvesting and Post-Harvest

Patience pays off here.

When to Harvest

Usually 6–10 months after planting, once the plants die back from frost or flowering.

How to Harvest

• Use a garden fork to gently lift the clump.

• Separate storage tubers (the sweet, edible part) from crown rhizomes (used for replanting).

• Handle gently—they bruise easily.

Storing for Sweetness

Tips for storing:

• Freshly dug tubers taste bland—let them cure in a cool, dark place for 1–2 weeks.

• Curing develops sweetness as natural sugars increase.

• Store cured tubers in a root cellar, basement, or refrigerator for up to several months.

I like to slice mine into salads right after curing, but they’re also delicious roasted or turned into syrup.

Frequently Asked Questions (FAQs)

Can I grow yacon in pots?
Yes, but choose large containers at least 20 gallons in size. The tubers need depth and space.

How long does yacon take to mature?
Between 6–10 months, depending on climate. Plant early for bigger harvests.

Is yacon frost hardy?
Not really. The plant dies back with frost, though crowns can survive mild winters if mulched.

Where can I buy yacon tubers in the U.S.?
Look for online specialty seed companies, organic nurseries, or gardener exchange groups in spring.

Final Thoughts

Growing yacon is one of the most rewarding gardening adventures I’ve tried. It combines the ease of potatoes, the size of sweet potatoes, and the fresh crunch of apples—all in one plant. Plus, it’s a fantastic conversation starter when neighbors spot those tall stalks in your yard.

If you’ve been looking for a unique, healthy, and productive crop, this is it. Plant yacon this season, and by harvest time, you’ll be enjoying crisp, sweet tubers straight from your garden.

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