Can You Grow Sweet Potatoes from a Potato? (Correct Method)

Sweet potatoes cannot be grown from regular potatoes—they're botanically unrelated plants. To grow sweet potatoes, you need sweet potato "slips" (sprouts) from actual sweet potatoes, not regular potatoes. This guide explains the scientifically correct propagation method with step-by-step instructions.

Why You Can't Grow Sweet Potatoes from Regular Potatoes

Many gardeners confuse sweet potatoes (Ipomoea batatas) with regular potatoes (Solanum tuberosum), but they belong to completely different plant families. Sweet potatoes are morning glory relatives, while regular potatoes are nightshades. This biological difference means regular potatoes cannot produce sweet potatoes—it's like trying to grow apples from orange seeds.

Characteristic	Sweet Potatoes	Regular Potatoes
Plant Family	Convolvulaceae (morning glory)	Solanaceae (nightshade)
Edible Part	Storage roots	Modified stems (tubers)
Propagation Method	Slips from sweet potato roots	"Seed" potatoes (tubers)
Climate Preference	Warm, 90-120 frost-free days	Cooler, 70-100 frost-free days

The Correct Way to Grow Sweet Potatoes: A Step-by-Step Guide

Phase 1: Creating Sweet Potato Slips (4-6 Weeks Before Planting)

Unlike regular potatoes that grow from "seed" potatoes, sweet potatoes require slips—sprouts grown from actual sweet potato roots. Here's how to do it properly:

1. Select healthy sweet potatoes: Choose disease-free, firm sweet potatoes (not grocery store varieties treated with sprout inhibitors). Organic sweet potatoes work best. The University of Georgia Extension recommends Covington, Beauregard, or Georgia Jet varieties for reliable slip production.
2. Start slips in water: Suspend half-submerged sweet potatoes in jars using toothpicks. Change water every 3-4 days. Roots will develop in water while shoots emerge above.
3. Alternative soil method: Bury sweet potatoes 1 inch deep in moist potting mix. Keep soil at 75-80°F (24-27°C). This method produces stronger root systems according to Penn State Extension research.

Phase 2: Transplanting Slips to Your Garden (After Last Frost)

Timing is critical—sweet potatoes need warm soil (65°F/18°C minimum) and 90-120 frost-free days. Here's what successful growers do:

• Soil preparation: Amend with 3-4 inches of compost. Sweet potatoes prefer loose, well-drained soil with pH 5.8-6.2. Avoid fresh manure which causes forked roots.
• Planting technique: Plant slips 12-18 inches apart in raised mounds 8-10 inches high. Bury 6 inches of the stem, leaving 2-3 leaves above soil.
• Watering schedule: Water deeply at planting, then reduce to 1 inch per week once established. Overwatering during final 3 weeks reduces sweetness.

Phase 3: Maintenance Through Harvest (90-120 Days)

Sweet potatoes need minimal care but require specific conditions to thrive:

Growth Stage	Timeline	Critical Actions
Root Development	Weeks 1-4 after planting	Maintain consistent moisture; apply 2-3" straw mulch
Vine Expansion	Weeks 5-8	Turn vines weekly to prevent rooting at nodes; no fertilizer needed
Tuber Bulking	Weeks 9-14	Reduce watering; monitor for sweet potato weevils
Harvest Ready	90-120 days	Leaves yellowing; soil cracking around roots

Common Mistakes That Prevent Sweet Potato Success

Based on USDA Agricultural Research Service data, these context-specific errors cause most failed crops:

• Using grocery store sweet potatoes: Most are treated with sprout inhibitors. Organic or seed-certified sweet potatoes are essential for slip production.
• Planting too early: Soil temperatures below 60°F (15°C) stunt growth permanently. Wait until soil reaches 65°F at 4" depth.
• Over-fertilizing: Excess nitrogen creates lush vines but tiny roots. Sweet potatoes need low-nitrogen, high-potassium soil.
• Harvesting incorrectly: Use a digging fork (not shovel) and handle roots gently—they bruise easily. Cure at 85-95°F for 5-10 days before storage.

Troubleshooting Your Sweet Potato Crop

When problems arise, these evidence-based solutions work best:

• No slips developing? Increase warmth to 80°F and ensure consistent moisture. Some varieties take 4+ weeks to sprout.
• Yellowing leaves? Could indicate nitrogen deficiency or fusarium wilt. Test soil before adding amendments.
• Small tubers? Overcrowding or excessive nitrogen are common culprits. Space plants 18" apart in rows 36" apart.
• Cracked roots? Inconsistent watering during bulking phase. Maintain even moisture in final 3 weeks.

Frequently Asked Questions

Can I grow sweet potatoes from store-bought sweet potatoes?

Only if they're organic. Most conventional grocery store sweet potatoes are treated with sprout inhibitors that prevent slip growth. Organic sweet potatoes or certified seed stock work best for reliable propagation.

How long does it take to grow sweet potatoes from slips?

Most varieties require 90-120 frost-free days from slip planting to harvest. Early varieties like 'O'Henry' mature in 90 days, while standard varieties like 'Beauregard' need 100-110 days for full development.

Why are my sweet potato vines flowering?

Flowering indicates stress—usually insufficient water or nutrients. While pretty, flowers divert energy from tuber development. Remove flower buds immediately to redirect energy to root growth for larger harvests.

Can I grow sweet potatoes in containers?

Yes, in 5-gallon buckets or larger containers with drainage holes. Use loose potting mix and plant 1-2 slips per container. Container-grown sweet potatoes need more frequent watering but can yield 3-5 pounds per pot with proper care.