Here’s how to grow sweet potatoes in water: push 3–4 toothpicks into a healthy root, rest it on a jar with the bottom half submerged, and keep it warm. Sprouts appear in about 2 weeks. Twist off 6-inch shoots, root them in fresh water for about 10 days, then plant these “slips” outdoors after frost.
| Question | Quick answer |
|---|---|
| What you grow in water | Slips (rooted sprouts), not the final crop |
| Time to first sprouts | About 2 weeks (Clemson HGIC) |
| Time to root a slip | About 10 days in fresh water (Clemson HGIC) |
| Best root | Organic or home-grown; many store roots are treated to stop sprouting |
| Planting out | After frost, when soil is above 65°F (Clemson HGIC) |
| Harvest | About 90–120 days after planting slips |
Can You Grow Sweet Potatoes in Water?
Yes, for the first stage. A jar of water is a simple slip factory. Clemson Cooperative Extension’s Home & Garden Information Center (HGIC) describes exactly this: suspend a sweet potato with toothpicks so the bottom half is under water, change the water weekly, and wait for sprouts. Those sprouts become slips, the transplants every sweet potato crop starts from.
What you can’t do well is grow full-size roots in a jar. The storage roots need a deep, loose medium. So how to grow sweet potatoes in water really means how to start them in water and finish them in soil, a large container or a deep media bed.
It’s one of the easiest kitchen projects in our list of plants that grow in water.
What Do You Need to Grow Sweet Potatoes in Water?
- A healthy, medium-size root. Clemson says roots from last year’s home harvest or organically grown roots sprout more readily, because most grocery store sweet potatoes were treated to resist sprouting.
- Quart jars (regular or wide-mouth) and 3–4 toothpicks per root.
- A warm spot with indirect light. WSU Extension notes sweet potato roots need heat to sprout, and cooler temperatures slow sprouting.
- Clean water and a second jar for rooting slips.
How to Grow Sweet Potatoes in Water Step by Step
- Insert toothpicks. Push 3–4 toothpicks into the root halfway between the two ends (Clemson).
- Set it on the jar. Let the toothpicks rest on the rim with the bottom half of the root submerged.
- Keep it warm. Choose a warm location with indirect sunlight.
- Change the water weekly. Clemson says cloudy water is a sign of bacterial growth. Top up as needed.
- Wait for sprouts. Clemson says sprouts appear in about 2 weeks.
- Harvest the sprouts. When sprouts are 6 inches or longer, grasp each near its base and twist or pull it free. Mississippi State Extension notes that cutting slips, rather than pulling them, helps reduce disease.
- Root the slips. Stand the sprouts in a jar of fresh water covering their bases. Roots form in about 10 days (Clemson).
That’s the whole method of how to grow sweet potatoes in water. A single root can produce several sprouts, so one jar may supply a small garden bed.
When and How Should You Plant the Slips?
The jar stage ends here. Knowing how to grow sweet potatoes in water gets you healthy slips; the planting stage turns them into a crop. Sweet potatoes are tender, warm-season plants. Clemson says not to plant until well after the last frost, with soil above 65°F. Mississippi State notes that slips are planted after soils warm and all danger of frost has passed.
- Spacing: Clemson plants slips 8–12 inches apart in rows 3 feet apart, about 3 inches deep.
- Containers: A large, deep container or grow bag works for patios. Use loose, well-drained media; see growing media.
- Water in well: Clemson recommends at least 1 inch of water a week, with uniform moisture.
- Keep the leaves: WSU Extension reported, from unpublished 2024 trial data, much higher root yield when lower leaves were left on slips at planting.
Rooted slips can also wait in water until planting time, or be potted up for extra growth first (Clemson). That flexibility is what makes how to grow sweet potatoes in water so beginner-friendly.
Which Varieties Should You Try?
| Variety | Days (Clemson) | Notes |
|---|---|---|
| ‘Beauregard’ | 90–100 | Fast to harvestable roots; stores well |
| ‘Covington’ | 95–110 | Uniform shape; stores better than Beauregard |
| ‘Vardaman’ | 100 | Compact, bush-type habit |
| ‘Murasaki’ | 100–120 | Purple skin, light flesh, long vines |
Home-grown roots of non-patented varieties are ideal for how to grow sweet potatoes in water. WSU warns that patented varieties may not be propagated on the farm, and Clemson lists ‘Covington’ with a plant patent number, so check the tag first.
What Mistakes Happen When You Grow Sweet Potatoes in Water?
| Mistake | Result | Fix |
|---|---|---|
| Using a treated grocery root | No sprouts | Organic or home-grown roots (Clemson) |
| Never changing the water | Cloudy, smelly water; rot | Change weekly (Clemson) |
| Cold room | Very slow sprouting (WSU) | Warm spot, indirect light |
| Uneven watering after planting | Cracked roots (Clemson) | Uniform watering, at least 1 inch a week |
| Planting out too early | Cold damage, stalled slips | Wait for soil above 65°F |
Most failures in how to grow sweet potatoes in water come from the first two rows: the wrong root and stale water.
How Do You Harvest and Cure Sweet Potatoes?
Harvest is the payoff for learning how to grow sweet potatoes in water months earlier. Clemson suggests harvesting when about 30% of roots are larger than 3½ inches across, and Clemson says sweet potatoes are usually ready 90–120 days after planting. Harvest before frost and handle roots gently; the skins bruise easily. Curing heals wounds and sweetens the roots. Clemson’s ideal is 85°F and 90% humidity for a week; at home, the warmest room for about 14 days works. Store cured roots above 50°F and never refrigerate them.
FAQs: How to Grow Sweet Potatoes in Water
How long does it take to grow sweet potatoes in water?
About 2 weeks for sprouts and about 10 more days to root each slip, per Clemson HGIC. The full crop takes 90–120 days after planting out.
Which part of the sweet potato goes under the water?
Submerge the bottom half, using toothpicks set halfway between the ends. Keep the water level steady so the lower half stays wet, and change it weekly.
What temperature works best for how to grow sweet potatoes in water?
Warm. WSU Extension sprouts roots at 80–85°F on heat mats, and Mississippi State keeps sprouting beds between 75 and 85°F. A warm room with bright, indirect light is the home version.
Can I learn how to grow sweet potatoes in water as a houseplant?
Yes. The leafy vine grows happily in a jar for a while as a decorative plant, though it won’t make large roots.
Is it cheaper to learn how to grow sweet potatoes in water than to buy slips?
Usually. One root can supply several slips. Buying certified slips is a good choice when you want guaranteed disease-free plants.
Is how to grow sweet potatoes in water the same as for regular potatoes?
No. They’re different plants, and regular potatoes are started from seed potatoes rather than water-rooted slips. For true potatoes, see how to grow potatoes hydroponically.
Related HydroponicEra Guides
Sources
- Clemson Cooperative Extension HGIC — Sweetpotato
- Mississippi State University Extension — Growing Sweet Potatoes at Home
- Washington State University Extension — Growing Sweetpotatoes in Western Washington: Slip Production (PDF)
- University of Arizona Cooperative Extension — Sweet Potatoes (PDF)
- Photo credits (Wikimedia Commons, edited with titles): Sweet potato sprouting slips by Geo Lightspeed7 (CC BY-SA 4.0); Sweet Potato by Gaurav Dhwaj Khadka (CC BY-SA 4.0)