How to Grow Yacons USA
On this page
Yacon needs a frost-free growing season of at least seven months and grows best between 65°F and 77°F (18-25°C), tolerating summer heat up to 104°F (40°C) if it's kept well watered — but its foliage is frost-tender, so start rhizome divisions indoors about two months before your last spring frost date and set them out once they're 6-12 inches tall with three or four sets of leaves. In the US, growers in Maine have matured a good crop in as little as four cool-season months (versus the six to seven months usually quoted), and a light frost that kills the top growth in fall won't harm — and can even improve — the roots still ripening underground.
The short answer
- Site
- soil pH 5.5–6.5
- Biggest risk
- Powdery mildew
Core growing advice on this page is checked against named horticultural sources — see References.
Yacon (Smallanthus sonchifolius)
3 sources cited · Verified
Quick Facts
At a Glance
Diseases
Pests
Soil & Growing Conditions
Growth Stages
Harvest & Storage
Plan your Yacons planting
When to sow and plant Yacons depends on your own frost dates. Check the USA vegetable planting calendar. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.
Growing Yacon in another region
Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.
Sources
The full list of 3 sources behind this guide (Cultivariable, Maine Organic Farmers and Gardeners Association (MOFGA), Useful Temperate Plants) is in the references of our UK guide to yacon; they describe the plant itself, which is the same wherever it grows.
Frequently Asked Questions
What soil pH does yacon need?
A pH of about 5.5–6.5. That span reflects genuine variation between the authorities we cite rather than a single agreed figure — the References section lists each source's exact range.
What problems affect yacon?
Our data links 3 diseases and 7 pests to this crop. See the sections above for each one and how to manage it.
Plan next season before the problems start
Almost everything on this page resolves to your own frost dates rather than the calendar — the last spring frost moves by roughly two months between zone 3 and zone 10. The USA Garden Planner works from your zone so the timing is already decided before the season starts.
Get the USA Garden Planner →Instant PDF download · Written for US growing conditions
How this guide is put together
The growing data on this page — sowing windows, pests, diseases, soil and site requirements — comes from named horticultural sources, listed in References below, checked against USDA hardiness-zone and frost-date data, with Cooperative Extension sources cited directly where one exists for a crop. An automated pipeline assembles that verified data into the page you're reading: it selects which facts to lead with and builds the surrounding prose and layout. It does not invent a date, a source or a number — where a verified value for a field isn't available, the page leaves it out rather than guessing. A person reviews and publishes each page; nothing goes live unverified.
Related Problem Guides
Last verified 2026-09-02
Related guides
More from the same group (roots & tubers):
Growing advice for your part of the USA
Timing and conditions change a lot inside one country. These guides cover frost dates and growing seasons region by region.
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Keep going
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.