How to Grow Sweet Potatoes — Any Climate
How to grow sweet potatoes anywhere in the world, without a calendar: wait for a soil temperature, not a date. Sweet Potatoes are heat-loving, frost-tender. Transplant rooted slips once soil is reliably warm and well past your last frost date. Give them full sun, space them 30-40 cm (12-16 in) apart, in raised hills to speed soil warming, and allow 85-120 days from transplant; needs sustained heat to size the tubers. These thresholds hold in any climate and either hemisphere.
When to plant sweet potatoes — the conditions to wait for
There is no universal date for sweet potatoes, because the same calendar month means completely different things at different latitudes and in opposite hemispheres. What does not change is the set of conditions the plant responds to.
| Condition | What this crop needs |
|---|---|
| Temperature class | Heat-loving, frost-tender |
| When conditions are right | Transplant rooted slips once soil is reliably warm and well past your last frost date |
| Light | Full sun |
| Spacing | 30-40 cm (12-16 in) apart, in raised hills to speed soil warming |
| Germination time | Grown from slips, not seed |
| Days to maturity | 85-120 days from transplant; needs sustained heat to size the tubers |
Observe, measure, decide
- Observe. Watch what your own garden does, not what a calendar says. When does standing water disappear in spring? Where does frost linger longest? Which corner warms first? A season of notes beats any regional average.
- Measure. Two instruments settle almost every timing question: a soil thermometer pushed 5-10cm (2-4in) into the bed at the same time each morning, and your own records of first and last frost. Soil temperature is the number that actually governs germination.
- Decide. Match the measurement to the crop's temperature class, then count backwards from your frost date using days-to-maturity. If the arithmetic does not fit your season, change the cultivar or the crop — not the date.
💡 The one instrument worth owning
A soil thermometer pushed 5-10 cm (2-4 in) into the bed, read at the same time each morning, answers more timing questions than any calendar. Soil temperature — not air temperature — governs whether seed germinates or rots.
Soil and site
Loose, well-drained soil, pH 5.8-6.2. Chilling injury occurs below 10°C (50°F) — genuinely marginal in any climate without a long, hot summer.
Watering
Moderate, even watering during establishment; reduce in the final weeks before harvest for better storage quality.
Spacing and layout
Space sweet potatoes 30-40 cm (12-16 in) apart, in raised hills to speed soil warming. Crowding is the most common cause of disappointing yields — plants compete for light and water, and poor airflow between them raises disease pressure sharply.
Companion planting
Thyme, oregano.
Common problems
Wireworm in some regions. Harvest before the first frost; cure at 26-29°C (80-85°F) and high humidity for several days to heal wounds and sweeten before storage.
Turn growing sweet potatoes into a written plan. The Global Vegetable Garden Planner (printable PDF) has the soil-temperature reference, crop rotation planner, sowing log and harvest tracker — 73 pages, no calendar required.
Frequently Asked Questions
When should I plant sweet potatoes?
Wait for conditions rather than a date. Transplant rooted slips once soil is reliably warm and well past your last frost date. This works identically in either hemisphere.
What temperature do sweet potatoes need?
They are a heat-loving, frost-tender crop. Germination takes Grown from slips, not seed once conditions are right.
How far apart should sweet potatoes be planted?
Space them 30-40 cm (12-16 in) apart, in raised hills to speed soil warming.
What usually goes wrong with sweet potatoes?
Wireworm in some regions. Harvest before the first frost; cure at 26-29°C (80-85°F) and high humidity for several days to heal wounds and sweeten before storage.
Last updated 25 August 2026
Tools That Help With This Crop
Use these links when the guide moves from reading into sowing, planting, watering, and keeping the crop healthy.
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.