How to Grow Sweet Potatoes: A Comprehensive Guide
Sweet potatoes thrive with warm weather, well-drained soil, and proper care; by starting with disease-free slips, providing consistent watering, and harvesting before the first frost, you can cultivate a bountiful crop of these nutritious and versatile root vegetables.
Understanding Sweet Potatoes
Sweet potatoes, Ipomoea batatas, are not actually potatoes at all! They are a member of the morning glory family and are grown from slips, not seeds. Knowing the basics of their growth requirements is key to success.
The Nutritional Powerhouse: Benefits of Growing Your Own
Beyond their delicious flavor, sweet potatoes are packed with nutrients, making them a healthy addition to any diet. Growing your own allows you to control the quality and ensure they are free from harmful chemicals. Here are just a few benefits:
- Rich in Vitamins: Excellent source of vitamin A (in the form of beta-carotene), vitamin C, and vitamin B6.
- High in Fiber: Promotes healthy digestion.
- Source of Minerals: Contains potassium, manganese, and copper.
- Antioxidant Properties: Beta-carotene and other antioxidants protect against cell damage.
- Freshness and Control: You know exactly where your food comes from and how it was grown.
The Step-by-Step Guide to Growing Sweet Potatoes
Successful sweet potato cultivation involves a few key steps, from preparing the soil to harvesting your bounty.
Prepare the Soil: Sweet potatoes thrive in well-drained, sandy loam soil. Amend heavy clay soil with compost and organic matter to improve drainage. The ideal soil pH is between 6.0 and 6.5.
Starting Slips: You can purchase slips from a reputable nursery or grow your own by sprouting a sweet potato in water. This is done by suspending the potato halfway in water using toothpicks. Sprouts (slips) will emerge from the potato. Once they reach 6-8 inches, carefully twist them off.
Planting Slips: Plant slips after the last frost when the soil has warmed to at least 65°F (18°C). Plant them 12-18 inches apart in rows that are 3-4 feet apart. Bury about two-thirds of the slip in the soil, leaving the top leaves exposed.
Watering: Water thoroughly after planting and keep the soil consistently moist, especially during the first few weeks. Once established, sweet potatoes are relatively drought-tolerant, but regular watering will result in a better yield. Avoid overhead watering to prevent fungal diseases.
Fertilizing: Sweet potatoes don’t require heavy fertilization. A side dressing of a balanced fertilizer (e.g., 10-10-10) a few weeks after planting can be beneficial. Avoid excessive nitrogen, as it can promote vine growth at the expense of root development.
Weeding: Keep the planting area free of weeds, especially when the plants are young. Once the vines spread, they will help suppress weed growth.
Pest and Disease Control: Sweet potatoes are generally pest-resistant, but watch out for sweet potato weevils and wireworms. Implement preventative measures like crop rotation and using row covers. Diseases are usually minimal with good drainage and airflow.
Harvesting: Harvest sweet potatoes before the first frost. Use a garden fork to carefully lift the plants, being careful not to damage the tubers.
Curing: Curing is an essential step for improving the flavor and storage life of sweet potatoes. Cure them in a warm (80-85°F or 27-29°C), humid (85-90%) environment for 7-10 days. This allows the skins to thicken and minor scratches to heal.
Storing: Store cured sweet potatoes in a cool (55-60°F or 13-16°C), dry, and well-ventilated place. Avoid refrigeration, as it can cause them to spoil. Properly cured and stored sweet potatoes can last for several months.
Common Mistakes to Avoid
Even experienced gardeners can make mistakes. Here are some pitfalls to avoid:
- Planting Too Early: Sweet potatoes are sensitive to cold and will not thrive in cool soil.
- Overwatering: Excessive watering can lead to root rot.
- Excessive Nitrogen: Too much nitrogen will result in lush vine growth but fewer potatoes.
- Damaging Tubers During Harvest: Handle sweet potatoes carefully to avoid bruising, which can lead to spoilage.
- Skipping the Curing Process: Curing is crucial for flavor and storage.
Choosing the Right Variety
Different varieties offer diverse flavors, textures, and growth characteristics. Consider these factors when choosing:
| Variety | Skin Color | Flesh Color | Flavor | Growing Season | Notes |
|---|---|---|---|---|---|
| Beauregard | Red | Orange | Sweet, Moist | 90-100 days | Popular, high-yielding |
| Georgia Jet | Red | Orange | Very Sweet, Moist | 90 days | Early maturing |
| Centennial | Orange | Orange | Sweet, Moist | 100-110 days | Classic variety |
| Japanese Sweet | Purple | White | Dry, Nutty | 110-120 days | Also known as Murasaki |
| Jewel | Copper | Orange | Sweet, Moist | 100-110 days | Good storage |
Frequently Asked Questions (FAQs)
1. How do I start sweet potato slips myself?
To start your own slips, select a healthy sweet potato and place it in a jar or glass with water covering the bottom half. Use toothpicks to suspend the potato. Keep the jar in a warm, bright location. In a few weeks, sprouts will emerge from the potato. Once the sprouts are 6-8 inches long, gently twist them off and place them in water until roots develop. Plant the rooted slips directly into the garden soil. Be sure to keep the water clean to prevent rot.
2. When is the best time to plant sweet potato slips?
The best time to plant sweet potato slips is after the last frost when the soil temperature has reached at least 65°F (18°C). Planting too early can result in poor growth or even death of the slips. Consider using a soil thermometer to ensure optimal conditions.
3. What kind of soil is best for sweet potatoes?
Sweet potatoes prefer well-drained, sandy loam soil with a pH between 6.0 and 6.5. Heavy clay soils should be amended with compost and other organic matter to improve drainage. Good drainage is essential to prevent root rot.
4. How often should I water my sweet potato plants?
Water sweet potato plants regularly, especially during the first few weeks after planting, to establish strong roots. Once established, they are relatively drought-tolerant, but consistent watering will result in a better yield. Water deeply but infrequently, allowing the soil to dry slightly between waterings. Avoid overhead watering to minimize the risk of fungal diseases.
5. Do sweet potatoes need fertilizer?
Sweet potatoes don’t require heavy fertilization. A side dressing of a balanced fertilizer (e.g., 10-10-10) a few weeks after planting can be beneficial. Avoid excessive nitrogen, as it can promote vine growth at the expense of root development.
6. How do I control pests on sweet potato plants?
Sweet potatoes are generally pest-resistant, but watch out for sweet potato weevils and wireworms. Implement preventative measures like crop rotation and using row covers. Handpicking pests can also be effective. For severe infestations, consider using organic insecticides approved for use on edible crops.
7. How do I know when my sweet potatoes are ready to harvest?
Sweet potatoes are typically ready to harvest 90-120 days after planting, depending on the variety. Harvest before the first frost. The foliage may start to turn yellow and die back, indicating that the potatoes are mature.
8. How do I harvest sweet potatoes without damaging them?
Use a garden fork to carefully lift the plants, being careful not to damage the tubers. Insert the fork a few inches away from the plant base and gently lift the soil. Handle the sweet potatoes carefully to avoid bruising, which can lead to spoilage. Damaged potatoes should be used quickly and not stored.
9. What is curing and why is it important?
Curing is an essential step for improving the flavor and storage life of sweet potatoes. Cure them in a warm (80-85°F or 27-29°C), humid (85-90%) environment for 7-10 days. This allows the skins to thicken and minor scratches to heal, preventing rot and enhancing the sweet flavor.
10. How should I store my sweet potatoes after curing?
Store cured sweet potatoes in a cool (55-60°F or 13-16°C), dry, and well-ventilated place. Avoid refrigeration, as it can cause them to spoil. Properly cured and stored sweet potatoes can last for several months.
11. Can I grow sweet potatoes in containers?
Yes, you can grow sweet potatoes in containers, but you’ll need a large container (at least 20 gallons) with good drainage. Choose a bush-type variety rather than a vining type. Provide adequate sunlight and water.
12. Are sweet potato leaves edible?
Yes, sweet potato leaves are edible and nutritious! They can be cooked and eaten like spinach or other leafy greens. Harvest young, tender leaves for the best flavor and texture.