How to Grow Sweet Potatoes
On this page
Sweet potatoes are ready to harvest 100–150 days after planting.
This is a frost-tender crop — it will not survive below about 1°C — so the growing year is built around starting it under cover and moving it out only once the risk of frost has passed.
The short answer
- Ready in
- 100–150 days
- Site
- 6+ hours of sun, soil pH 5–7
- Biggest risk
- Sweetpotato black rot
Core growing advice on this page is checked against named horticultural sources — see References.
Sweet Potato (Ipomoea batatas)
9 sources cited · Verified
Soil & Growing Conditions
Soil pH range
Span reflects genuine variation between the cited authorities, not a single agreed figure.
Quick Facts
| Factor | Value |
|---|---|
| Soil pH | 5 - 7 |
| Sunlight | 6-6 hours direct sun |
| Germination temp | 24°C |
| Optimal growing temp | 18-28°C |
| Minimum survivable temp | 1°C |
| Time to harvest | 100-150 days |
| Drainage | Moisture-retentive, free-draining |
| Lifecycle | perennial |
| Edible parts | storage roots |
At a Glance
Growth Stages
| Stage | BBCH | Notes |
|---|---|---|
| Slips & establishment | 0 | Grown from rooted cuttings ("slips") rather than seed tubers, available from online veg plant suppliers from late April. Pot up and grow on under cover until frost risk has passed. RHS. |
| Planting out | 3 | Plant out at least 30cm apart in late spring or early summer, once all frost risk has passed. RHS. |
| Vining growth | 6 | Trailing or climbing stems easily reach 1.5m or more in length as the plant bulks up through summer, well before any sign of the tubers developing below. RHS. |
| Harvest & curing | 8 | Most varieties need at least four to five months from planting; "Bonita" takes about 100 days. Harvest once the leaves yellow and die back in early autumn, before any frost -- tip the plant out of its container or lift with a fork. Dry tubers in warm sunshine for a few days to improve storage, though they generally keep for only a few weeks. RHS. |
Harvest & Storage
When to pick: RHS: "Bonita" takes "about 100 days from planting slips to harvesting"; most varieties require "at least four to five months"; harvest "once the leaves turn yellow and die back in early autumn, before any frost". UMD: days to maturity "85 to 120"; check root size "after 80 to 85 days because they don't stop growing"; roots "can start to split when overgrown"; harvest "before a frost".
Storage
Cure and store in cool, dry conditions for long-term keeping
Diseases
Pests
Nutrient Issues
Sweet Potato, Slip to Harvest
Plan your Sweet Potatoes planting
Timing for Sweet Potatoes follows soil temperature and frost, not the calendar date. The Global vegetable planting calendar explains the method. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.
Growing Sweet Potato in another region
Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.
Sources
These 2 sources are specific to this region. The full list of 9 sources behind this guide (Clemson Cooperative Extension, FAO EcoCrop, GBIF and others) is in the references of our UK guide to sweet potatoes; they describe the plant itself, which is the same wherever it grows.
Frequently Asked Questions
How long do sweet potatoes take to grow?
Typically 100–150 days, depending on cultivar and growing conditions.
What soil pH do sweet potatoes need?
A pH of about 5–7. 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 sweet potatoes?
Our data links 2 diseases and 2 pests to this crop. See the sections above for each one and how to manage it.
Plan next season before the problems start
This page gives you the thresholds; the planner turns them into your own calendar. It works from what you can observe and measure in your garden rather than from dates written for somebody else’s latitude.
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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 international horticultural research and extension sources. 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.
Last verified 2026-09-02
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.