When To Pick Sweet Potatoes?
Knowing when to harvest your sweet potatoes is crucial for maximizing their sweetness and storage potential. Generally, sweet potatoes are ready to harvest 90-120 days after planting, but relying on this timeframe alone can be misleading. It’s more reliable to look for specific visual cues and perform a test dig.
Introduction: The Sweet Rewards of Patience
Growing sweet potatoes can be incredibly rewarding. These vibrant root vegetables, packed with nutrients and bursting with flavor, offer a delicious addition to any meal. However, unlike some crops that practically shout when they’re ready to harvest, sweet potatoes are a bit more secretive. Picking them too early results in smaller, less sweet potatoes that don’t store well. Harvesting too late can lead to frost damage or rot in the ground. Mastering the art of timing is essential for reaping the full benefits of your sweet potato harvest.
Signs Your Sweet Potatoes Are Ready
Several indicators can help you determine if your sweet potatoes are ready for harvest:
- Days to Maturity: As mentioned, most varieties mature in 90-120 days. Keep accurate planting records to track this.
- Yellowing Vines: While some yellowing is normal, a significant yellowing or die-off of the vines, especially after a period of strong growth, suggests maturity. Note: This is more reliable in regions with distinct seasons.
- Small Cracks in the Soil: Check around the base of the plants for small cracks in the soil. These can indicate that the sweet potatoes are pushing against the earth.
- Test Dig: The most reliable method is to carefully dig around the base of one plant and gently lift a few sweet potatoes. Examine their size and skin thickness. Mature sweet potatoes will be a desirable size for your variety and have firm, unblemished skin.
The Test Dig: Your Best Bet
The test dig is crucial. Don’t rely solely on the other indicators. Here’s how to perform a test dig correctly:
- Choose a plant that represents the average size and vigor of your crop.
- Use a garden fork (rather than a shovel) to avoid damaging the sweet potatoes.
- Carefully insert the fork about 12 inches away from the plant’s crown.
- Gently loosen the soil around the plant.
- Lift the plant to expose the sweet potatoes.
- Check the size, skin thickness, and overall appearance of the sweet potatoes.
- If they are not ready, re-cover the plant carefully and wait a week or two before testing again. You can eat the sweet potatoes you unearthed.
Harvesting Sweet Potatoes: A Gentle Approach
Once you’ve determined your sweet potatoes are ready, it’s time to harvest. Handle them with care to avoid bruising, as this can lead to rot during storage.
- Choose a dry day for harvesting.
- Use a garden fork to carefully loosen the soil around the plants.
- Gently lift the plants, being mindful not to damage the sweet potatoes.
- Brush off any excess soil, but don’t wash them.
- Leave the sweet potatoes to cure in a warm, humid place for 7-10 days.
Curing Sweet Potatoes: Enhancing Flavor and Storage
Curing is essential for developing the sweet potato’s flavor and improving its storage life. Curing involves:
- Creating Ideal Conditions: A temperature of 80-85°F (27-29°C) and a humidity level of 85-90% are ideal.
- Proper Ventilation: Ensure good air circulation to prevent mold growth.
- Duration: Cure for 7-10 days.
- Result: Curing converts starches into sugars and heals minor cuts and bruises, which helps prevent spoilage.
Common Mistakes to Avoid
Several common mistakes can compromise your sweet potato harvest:
- Harvesting Too Early: Leads to small, bland potatoes that don’t store well.
- Harvesting Too Late: Increases the risk of frost damage or rot.
- Damaging the Potatoes: Bruising or cutting the sweet potatoes during harvest can lead to rot.
- Skipping the Curing Process: Neglecting to cure sweet potatoes reduces their sweetness and storage life.
- Washing Before Curing: Washing sweet potatoes before curing increases the risk of rot.
Table: Comparing Sweet Potato Varieties and Maturity Times
| Variety | Maturity Time (Days) | Skin Color | Flesh Color |
|---|---|---|---|
| Beauregard | 90-100 | Red | Orange |
| Centennial | 100-110 | Copper | Orange |
| Georgia Jet | 90 | Red | Orange |
| Japanese/Oriental | 110-120 | Purple | White |
| Jewel | 100-110 | Copper | Orange |
| Vardaman | 100-110 | Copper | Deep Orange |
FAQ: Frequently Asked Questions
Can I harvest sweet potatoes after the first frost?
If a light frost has only touched the vines, you can still harvest the sweet potatoes. However, if the ground has frozen, the sweet potatoes are likely damaged and should be harvested immediately. Handle them carefully and use them as soon as possible, as their storage life will be significantly reduced. Frost-damaged sweet potatoes are prone to rot.
How do I store sweet potatoes properly after curing?
After curing, store sweet potatoes in a cool, dry, and dark place with good ventilation. The ideal temperature is 55-60°F (13-16°C). Avoid storing them in the refrigerator, as this can cause chilling injury. Properly cured and stored sweet potatoes can last for several months.
What if my sweet potato vines are still green and healthy after 120 days?
In warmer climates with long growing seasons, sweet potato vines may remain green and healthy for longer than 120 days. Perform a test dig to assess the maturity of the potatoes. If they are a desirable size and have firm skin, they are likely ready to harvest, even if the vines are still thriving.
Can I eat sweet potato leaves?
Yes, sweet potato leaves are edible and nutritious. They can be eaten raw in salads or cooked like spinach. Harvest young, tender leaves for the best flavor. Avoid eating leaves from plants that have been treated with pesticides.
What causes sweet potatoes to crack in the ground?
Cracking can be caused by inconsistent watering or fluctuating soil moisture levels. Try to maintain consistent moisture throughout the growing season. Adding organic matter to the soil can also help improve water retention.
My sweet potatoes are small. What could be the reason?
Small sweet potatoes can be caused by several factors, including poor soil fertility, inadequate watering, short growing season, or overcrowded plants. Ensure well-draining, nutrient-rich soil, provide consistent watering, and space plants adequately.
Why do some sweet potatoes have a bitter taste?
A bitter taste in sweet potatoes can be caused by stress during growth, such as nutrient deficiencies or drought. Also, some varieties are naturally more prone to bitterness. Ensure proper soil conditions and consistent watering.
How can I tell if a sweet potato is rotten?
Rotten sweet potatoes will have soft spots, a foul odor, and may leak fluid. Discard any sweet potatoes that show signs of rot to prevent it from spreading to other potatoes.
Can I save sweet potato slips from my harvested potatoes?
Yes, you can save sweet potato slips for next year’s planting. Place a sweet potato in a jar of water, with the bottom half submerged. Place the jar in a warm, sunny location. Slips will sprout from the potato. Once they are 6-8 inches long, gently twist them off and root them in water before transplanting them into the garden. This allows you to grow your favorite varieties year after year.
What’s the best soil for growing sweet potatoes?
Sweet potatoes prefer well-drained, sandy loam soil with a slightly acidic pH (6.0-6.5). Heavy clay soils can hinder root development. Amending the soil with compost or other organic matter can improve drainage and fertility.
Are there any pests or diseases that affect sweet potatoes?
Common pests of sweet potatoes include sweet potato weevils, wireworms, and flea beetles. Diseases include stem rot and black rot. Implement preventative measures such as crop rotation, weed control, and using disease-resistant varieties. Monitor plants regularly for signs of infestation or disease.
What if I don’t have a dedicated space for curing sweet potatoes at the proper temperature and humidity?
While ideal conditions are best, you can still cure sweet potatoes without them. Find the warmest, most humid location in your house. A bathroom after a shower can work, or near a furnace. You may need to extend the curing time slightly. While not perfect, this is far better than not curing them at all. Improvised curing will still improve flavor and storage life.