How to Grow Sweet Potatoes from Potatoes

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Learn how to grow sweet potatoes from potatoes with this beginner-friendly guide. Discover how to sprout slips, plant them properly, and harvest a thriving homegrown sweet potato crop.

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Growing sweet potatoes is one of the most satisfying things you can do in your garden. There’s something almost magical about turning one humble sweet potato into an entire harvest. If you’ve never grown them before, don’t worry — they’re surprisingly forgiving, incredibly productive, and perfect for beginners.

Unlike regular potatoes, sweet potatoes don’t grow from “seed potatoes.” Instead, they grow from slips — small rooted sprouts that develop from a mature sweet potato. Once you understand this one key difference, everything else becomes simple.

In this guide, I’m walking you through the entire process step by step. From choosing the right sweet potato to harvesting big, beautiful tubers, you’ll have everything you need to grow your own thriving crop.

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Understanding How Sweet Potatoes Grow

Before we dig in (literally), it helps to understand how sweet potatoes actually grow. This small bit of knowledge will make the whole process feel much easier and more intuitive.

Sweet potatoes grow from slips, which are green shoots that sprout from a mature sweet potato. These shoots form roots when placed in water or soil, and once planted in warm ground, they develop into sprawling vines. Beneath those vines, new sweet potatoes begin forming underground.

Unlike regular potatoes, which grow from chunks of potato planted directly into soil, sweet potatoes need warm temperatures and a longer growing season. They love heat, sunshine, and loose soil. If you can provide those three things, you’re already halfway there!

Choosing the Right Sweet Potato

Not all sweet potatoes are created equal when it comes to growing. While you can technically sprout one from the grocery store, there are a few important things to consider first.

Organic sweet potatoes are your best bet. Many conventionally grown sweet potatoes are treated with sprout inhibitors to extend shelf life, which can make them harder to grow. Organic varieties are much more likely to sprout successfully.

If possible, buy from a local farmers’ market or garden center. You’ll often find varieties that grow especially well in your climate. Some sweet potatoes mature faster, which is helpful if you live in a cooler region with a shorter summer.

Choose firm, healthy sweet potatoes with no soft spots, mold, or shriveling. Medium-sized ones tend to sprout more reliably than very large ones.

How to Grow Sweet Potato Slips

Start Sprouting Indoors

About 6–10 weeks before your last expected frost, it’s time to start your slips — but instead of using jars of water, I prefer growing mine in shallow trays of soil. Lay your sweet potato horizontally in a tray filled with 2–3 inches of moist potting mix, pressing it gently into the soil so it’s about halfway covered.

I like to get an early start by doing this in January since they need time to grow the slips and then even more time to grow the roots before planting in warm soil outside.

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Place the tray in a warm, bright spot. Sweet potatoes love heat, so aim for temperatures above 70°F if possible. My indoor mini greenhouses with grow lights are the perfect environment for starting mine. Within a couple of weeks, you’ll notice green sprouts forming along the top. Growing them in soil instead of water produces sturdier, thicker slips right from the start.

Keep the soil lightly moist but never soggy. You don’t want the potato sitting in wet conditions, just consistently damp soil to encourage healthy sprouting. This method reduces rot issues and gives you strong slips that transition easily to the garden.

Remove and Root the Slips

Once the sprouts reach about 4–6 inches long, gently twist them off the sweet potato. Don’t worry — removing them won’t harm the original potato.

Place the slips in a shallow container of water with the stems submerged. Within several days, roots will begin forming along the bottom. This is when things start to feel exciting — you’re officially growing your own plants!

Let the roots grow to about an inch long before planting. Strong roots give your slips the best start in the garden.

Harden Off Before Planting

Sweet potato slips are tender and sensitive to cold. Before planting outdoors, gradually introduce them to outdoor conditions over 7–10 days.

Start by placing them outside in a sheltered spot for a few hours each day, increasing exposure gradually. This process, called hardening off, reduces transplant shock.

Never rush this step. Sweet potatoes absolutely hate cold soil, and planting too early is one of the most common mistakes gardeners make.

Preparing the Soil for Sweet Potatoes

Sweet potatoes thrive in loose, well-draining soil. Heavy clay or compacted soil can stunt growth and produce misshapen tubers.

Work compost into the soil to improve texture and fertility. Avoid high-nitrogen fertilizers, which encourage leafy growth at the expense of tuber development. You want energy going underground, not just into vines.

Raised beds work beautifully for sweet potatoes because they warm up faster in spring. If you garden in containers, choose large grow bags or deep pots to give roots plenty of room to expand.

Soil temperature should consistently be at least 65°F before planting. Warmer is even better.

Planting Your Sweet Potato Slips

Plant slips 12–18 inches apart in rows spaced about 3 feet apart. Sweet potato vines spread widely, so give them room.

Bury the rooted portion of the slip and at least one or two nodes of the stem. These nodes will develop additional roots, strengthening the plant and increasing yield.

Water thoroughly after planting. Consistent moisture is important during the first couple of weeks while plants establish themselves.

Mulching around the plants helps retain moisture, suppress weeds, and warm the soil — all things sweet potatoes love!

Caring for Growing Sweet Potatoes

Sweet potatoes are relatively low-maintenance once established, but a few simple practices will dramatically improve your harvest.

Water consistently, especially during dry periods. While sweet potatoes are somewhat drought-tolerant, uneven watering can reduce tuber size. Aim for about 1 inch of water per week.

Keep weeds under control early in the season. Once vines spread and cover the ground, they naturally suppress weeds.

Avoid pruning vines. Those sprawling stems are feeding energy back into the developing tubers below. Let them grow freely! Plus, the foliage of these plants is so beautiful!

When and How to Harvest Sweet Potatoes

Most sweet potato varieties mature in 90–120 days. You’ll know harvest time is approaching when the leaves begin yellowing, especially as temperatures cool.

Before the first frost, carefully dig around the base of the plant with a garden fork. Sweet potatoes can be fragile, so avoid piercing them.

Shake off excess soil, but do not wash them immediately. Instead, cure them in a warm, humid space (around 80–85°F) for 7–10 days. Curing improves flavor and extends storage life.

After curing, store them in a cool (not cold), dry place. Properly cured sweet potatoes can last for months.

Growing Sweet Potatoes in Containers

If you’re short on space, don’t let that stop you. Sweet potatoes grow beautifully in containers. This is most likely my favorite method of growing potatoes because I do not like to dig. I can tip my containers over and harvest the potatoes easily.

Choose a container at least 15–20 gallons in size. Fill it with high-quality potting mix blended with compost for added nutrients.

Container-grown sweet potatoes require more frequent watering, as pots dry out faster than garden beds. Keep soil consistently moist but never soggy.

You may harvest slightly smaller tubers, but the convenience and space-saving benefits make container growing well worth it.

Common Mistakes to Avoid

Planting too early is the biggest mistake gardeners make. Cold soil can stunt or kill slips, setting your harvest back significantly.

Using heavy, compacted soil leads to twisted, undersized tubers. Always prioritize loose, well-draining soil.

Over-fertilizing with nitrogen creates lush vines but poor root development. Keep feeding balanced and minimal.

Finally, harvesting too soon can reduce yields. Patience truly pays off with sweet potatoes!

Conclusion

Growing sweet potatoes from potatoes is simpler than most people realize. With a little patience at the beginning and plenty of warmth throughout the season, you can turn one sweet potato into a generous harvest.

Start with healthy organic sweet potatoes, sprout strong slips, wait for warm soil, and give your plants space to thrive. From there, nature does most of the work.

There’s nothing quite like digging up your own homegrown sweet potatoes at the end of the season. Once you try it, you may never go back to store-bought again!

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