Sweet Potatoes: Tips for Growing the Best, Sweetest, and Biggest Harvest

This post is all about growing the best sweet potatoes.

When it comes to growing sweet potatoes, it took me years of trial and error to truly master the process.

I’ve battled poorly formed roots, vines that grew everywhere but produced nothing worthwhile, and even sweet potatoes that tasted bland instead of, well, sweet.

Over time, I learned that the secret to growing the best sweet potatoes is all about preparation, timing, and a little bit of patience.

Let me share what I’ve learned so you can grow your own sweet and sizeable harvest!

Choosing the Right Variety

Not all sweet potatoes are created equal. Some varieties are better suited for certain climates, while others are bred for extra sweetness or size.

I’ve had the most success with:

Beauregard: A reliable variety with sweet, deep-orange flesh.
Covington: My go-to for consistent yields and great flavor.
Japanese (Murasaki): A delicious purple-skinned variety for something unique.

Pro Tip: Check with local gardening stores or extension offices to find varieties that thrive in your region.

Start with Healthy Slips

Sweet potatoes are grown from slips, which are shoots grown from mature sweet potatoes.

Here’s how I ensure my slips are top-notch:

Grow Your Own Slips: I start by placing an organic sweet potato in a jar of water, half-submerged. After a few weeks, slips (shoots) start to grow. Once they’re 6-8 inches long, I gently twist them off and place them in water until roots develop.
Buy from a Reputable Source: If time is short, purchase slips from a trusted garden center to ensure they’re disease-free.

Healthy slips = healthy plants. It’s that simple.

The Secret is in the Soil

Sweet potatoes love well-drained, sandy soil with a slightly acidic pH (5.5–6.5).

Here’s how to prep the soil:

Add Compost: Before planting, work a generous amount of compost into the soil to boost nutrients and improve drainage.
Mound It Up: Sweet potatoes grow best in raised rows or hills, about 8–10 inches high. This improves drainage and gives the roots room to expand.
Avoid Nitrogen Overload: Too much nitrogen encourages leafy growth instead of tubers. Use a balanced fertilizer, like one labeled for root vegetables.

Pro Tip: If your soil is clay-heavy, consider adding sand to lighten it up.

Timing is Everything

Sweet potatoes need warm weather and a long growing season (90–120 days). Plant them when the soil temperature consistently stays above 60°F, usually 2–3 weeks after the last frost.

I learned this the hard way one year when I planted too early, and the slips struggled to take root in the chilly soil. Waiting for the right temperature makes all the difference.

Proper Planting Technique

When planting your slips, spacing and depth are key:

Space Them Out: Plant slips 12–18 inches apart in rows that are 3–4 feet apart. Sweet potatoes need room to spread!
Plant Deeply: Bury slips so that two leaf nodes are under the soil and the leaves are above ground. This encourages strong root development.
Water Well: Give your newly planted slips a good soak to help them settle in.

Care and Maintenance

Sweet potatoes are relatively low-maintenance once established, but here are a few tricks to maximize your yield:

Water Consistently: Water regularly during the first few weeks to help the slips establish roots. Once the vines take off, water deeply once a week. Too much water late in the season can lead to splitting.
Weed Sparingly: Sweet potato vines will eventually smother most weeds, but keep the area weed-free early on to reduce competition.
Mulch to Retain Moisture: A layer of straw or mulch helps keep the soil warm and moist while preventing weeds.
Prune Sparingly: If the vines start taking over, gently guide them back toward the rows, but don’t over-prune—those vines feed the tubers!

Harvesting for Maximum Sweetness

Sweet potatoes are ready to harvest when the leaves start to yellow, usually 90–120 days after planting.

Here’s what I do:

Use a Garden Fork: Carefully loosen the soil around the plants, keeping the roots intact.
Cure for Sweetness: This step is critical! Sweet potatoes need to cure for 1–2 weeks at 80–85°F with high humidity to develop their sweetness fully. I lay mine in a warm, ventilated area and cover them with a cloth to hold in moisture.

Pro Tip: Handle sweet potatoes gently during harvest to avoid bruising, which can lead to rot.

Why Grow Your Own Sweet Potatoes?

Homemade sweet potatoes beat store-bought in every way:

Flavor: Homegrown sweet potatoes are naturally sweeter and fresher.
Variety: You can grow unique varieties that aren’t available at the store.
Cost: A few slips can yield pounds of sweet potatoes for a fraction of the cost.
Satisfaction: There’s nothing like pulling up a big, beautiful tuber after months of care.

FAQs About Growing Sweet Potatoes

1. How much sun do sweet potatoes need?
They thrive in full sun—at least 6–8 hours a day.

2. Can I grow sweet potatoes in containers?
Absolutely! Use a large container (at least 20 gallons) with well-draining soil and plenty of room for the vines to trail.

3. What causes small or stringy sweet potatoes?
This usually happens if the soil is too compacted, poorly drained, or lacks nutrients. Stick to loose, sandy soil and fertilize appropriately.

4. How do I store harvested sweet potatoes?
After curing, store them in a cool, dry place (55–60°F) with good ventilation. They can last for several months if stored properly.

5. Can I save sweet potatoes for next year’s slips?
Yes! Choose the healthiest tubers and store them until it’s time to start slips in late winter.

Growing sweet potatoes is one of the most rewarding gardening experiences I’ve had. With these tips and a little patience, you’ll be on your way to harvesting a sweet, delicious crop that’ll leave you wondering why you ever bought them from the store. Happy gardening!

Have questions or your own sweet potato growing tips? Let me know in the comments below!