Growing sweet potatoes is a great way to diversify your garden with a tasty and nutritious crop. This root vegetable, also known as yam or sweet potato, is becoming increasingly popular among home gardeners. Sweet potatoes thrive in warm weather, loose soil, and proper care — and their yield depends heavily on following the key steps of planting. As noted by the Baltimore Chronicle, even beginners can succeed with sweet potatoes if they stick to proven advice.
What You Should Know About Sweet Potatoes Before Planting
Sweet potatoes are a heat-loving crop native to South America. Their roots have a sweet flavor and are packed with nutrients like fiber, vitamins A, C, E, and potassium. They grow well in open soil provided temperatures stay above 20°C (68°F).
Before planting, it’s important to understand that sweet potatoes are not grown from seeds but from sprouts (slips) that are cultivated from mature tubers. Therefore, the planting process begins several weeks before moving them into open soil.
When to Plant Sweet Potatoes in the U.S.
The best time to plant sweet potatoes is late May to early June, once the danger of frost has completely passed. Sweet potatoes are sensitive to cold, so there’s no need to rush.
The soil temperature should be no lower than 15°C (59°F), and the air temperature should be consistently above 20°C (68°F). In southern regions of the U.S., this might be mid-to-late May, while northern areas may need to wait until early June.
Factors Affecting Planting Time:
- Local climate
- Sweet potato variety
- Soil and air temperature
- Availability of slips
How to Prepare Sweet Potato Slips
Since sweet potatoes are not grown from seeds, you need to grow slips (sprouts) from tubers. This can be done at home using a warm place and either water or soil.
Steps to Prepare Slips:
- Choose a healthy, undamaged tuber.
- Place it in water or slightly moist soil, partially submerged.
- Keep it on a warm, sunny windowsill.
- After 2–3 weeks, sprouts will begin to grow.
- When the sprouts are 15–20 cm (6–8 inches) long, gently break them off and root them in water.
Once the sprouts develop roots at least 1 cm (0.4 inches) long, they’re ready to be planted in open soil.
How to Prepare Soil for Sweet Potatoes
Sweet potatoes grow best in light, loose, well-drained soil with a neutral to slightly acidic pH (5.5–6.5).
To prepare your garden bed:
- Dig deeply, around 20–25 cm (8–10 inches)
- Remove weeds and large soil clumps
- Add compost or well-rotted manure
- Ensure good drainage
Soil Type Comparison for Sweet Potato Growing
| Soil Type | Suitability for Sweet Potatoes | Improvement Tips |
|---|---|---|
| Loam | Moderate | Add sand and compost |
| Sandy | Excellent | Maintain consistent moisture |
| Clay | Poor | Improve drainage |
| Black soil | Excellent | Monitor moisture levels |
How to Plant Sweet Potatoes in Open Ground
Once your slips are ready and temperatures are stable, you can plant sweet potatoes in garden beds. It’s best to plant in the morning or evening on a cloudy day.
Step-by-Step Planting Guide:
- Prepare beds 80–100 cm (31–39 inches) wide and 20–30 cm (8–12 inches) high.
- Space rows 60–70 cm (24–28 inches) apart and slips 30 cm (12 inches) apart.
- Dig holes 10–15 cm (4–6 inches) deep.
- Place one rooted slip in each hole at an angle.
- Water thoroughly with warm water.
During the first few days after planting, it’s crucial to maintain high soil moisture to help the slips establish well.
How to Care for Sweet Potatoes After Planting
Sweet potato care is not difficult but requires consistency.
Key Care Tasks:
- Watering. Keep the soil moist but not waterlogged, especially during the first month.
- Weeding. Sweet potatoes dislike competition from weeds.
- Loosening the Soil. Improves root aeration.
- Fertilizing. Apply phosphorus-potassium fertilizers once a month.
In August, reduce watering to avoid tuber rot before harvest.
When and How to Harvest Sweet Potatoes
Sweet potatoes are ready for harvest 90–120 days after planting, typically in September. The first sign of maturity is yellowing and wilting leaves.
Tips for Harvesting:
- Use a shovel or fork to gently lift the tubers
- Avoid damaging them, as they don’t store well if bruised
- Let the roots dry in open air for 2–3 hours
After harvest, cure the sweet potatoes in a warm place for 10–14 days — this improves taste and shelf life.
How to Store Sweet Potatoes
Store sweet potatoes in a dry, dark, and well-ventilated area at +13 to +16°C (55–61°F). Avoid storing in the fridge — cold temperatures can harm the roots.
To prevent spoilage:
- Don’t wash them before storing
- Avoid bruises or cuts
- Use wooden or cardboard boxes
Common Mistakes in Growing Sweet Potatoes
Even experienced gardeners sometimes make mistakes that reduce yields.
Most Common Mistakes:
- Planting too early in cold soil
- Excessive watering after August
- Growing in heavy clay soil
- Planting slips that aren’t well-rooted
Avoiding these mistakes will help ensure a successful harvest even in challenging conditions.
Earlier we wrote about how to properly plant daikon for a bountiful harvest.