Nothing’s more frustrating than digging up your sweet potatoes, only to find them disappointingly small after months of waiting.
Whether you’re a seasoned gardener or a beginner, harvesting a crop that doesn’t meet your expectations can be disheartening.
But don’t worry – small sweet potatoes are a common issue, and understanding what went wrong this season can lead to big improvements next time.
With a few key insights, you can learn exactly why those tubers came up smaller than expected and what to do differently for a bountiful harvest in the future.
Sweet Potatoes Too Small? Here’s What You Need to Know at Harvest!
Here’s everything you need to know to troubleshoot small sweet potatoes and set yourself up for success next growing season!
1. Timing is Everything: The Importance of Harvesting at the Right Time
One of the most common reasons for small sweet potatoes is premature harvesting. Sweet potatoes need a long growing season, ideally between 90 and 120 days of warm weather, to reach their full size.
If they’re harvested too early, they won’t have had enough time to bulk up.
To check if they’re ready, observe the leaves: when the vines start yellowing and dying back, it’s usually a good sign that they’re ready to harvest.
Tip: Next season, mark your planting date on a calendar or use a garden app to track the days. Ensure you wait for at least 90 days, preferably 100+, before digging them up for best results.
2. Soil Quality: Sweet Potatoes Thrive in Loose, Well-Draining Soil
Sweet potatoes are root vegetables, which means they need plenty of room to grow underground. Compact or heavy soils, like clay, restrict root expansion, resulting in smaller tubers.
They grow best in loose, sandy, or loamy soils that allow roots to spread easily. If your soil is dense, it may be preventing sweet potatoes from reaching their full potential.
Fix: Before planting, work organic matter, like compost or aged manure, into the soil to improve its texture. Raised beds can also be a great option to achieve that light, well-draining environment sweet potatoes love.
3. Fertilization Mistakes: Avoiding Excess Nitrogen
Fertilization can be a double-edged sword with sweet potatoes. While they need nutrients to grow, too much nitrogen promotes leafy vine growth at the expense of the tubers.
This often results in lush foliage above ground but smaller-than-expected sweet potatoes below.
Nitrogen encourages leaf growth, so if you’re seeing a lot of leaves but small roots, your plants might be overfed on nitrogen.
Solution: Use a balanced or low-nitrogen fertilizer for sweet potatoes, especially after they’ve established themselves. A potassium-rich fertilizer can promote root growth and help produce larger tubers.
4. Watering Issues: Finding the Right Balance
Water is essential for sweet potato growth, but it’s all about balance. Inconsistent watering—either too much or too little—can hinder tuber development.
Overwatering, especially in heavy soils, can cause roots to rot, while underwatering can stunt growth.
Aim for consistent moisture, especially during the first few weeks after planting and in the tuber-bulking stage (about 70-90 days after planting).
Tip: Water deeply, but infrequently, allowing the soil to dry slightly between waterings. A layer of mulch can help retain moisture and prevent fluctuations.
5. Sunlight Matters: Sweet Potatoes Need Plenty of Sun
Sweet potatoes are sun-lovers.
They need at least six to eight hours of full sun daily to grow well. If they’re planted in a shaded or partially shaded area, they won’t get the energy they need for tuber development, leading to smaller harvests.
Lack of sunlight means the plants can’t photosynthesize effectively, which stunts root growth.
Solution: Make sure to plant sweet potatoes in an area with full sun exposure. If your garden is limited on space, consider container planting or raised beds in sunny spots.
6. Choosing the Right Varieties for Your Climate
Not all sweet potato varieties perform the same in every region. Some varieties are better suited for longer, warmer climates, while others can tolerate cooler growing conditions.
Choosing a variety that doesn’t match your local climate can lead to subpar results, including smaller tubers.
Suggestion: Research and select varieties known to perform well in your growing zone. For instance, ‘Beauregard’ and ‘Georgia Jet’ are popular varieties that tend to produce well in a range of climates.
Final Thoughts
Growing sweet potatoes can be incredibly rewarding, but like all gardening, it’s a learning process.
Small sweet potatoes may be disappointing, but understanding why they happen is the first step to avoiding the problem in future harvests.
By timing your harvest, amending your soil, watching your watering, and choosing the right varieties, you can boost your chances of pulling up those big, hearty tubers you’ve been dreaming of.
Next season, try these tips and watch your garden flourish!