Can You Grow Sweet Potatoes from Regular Potatoes? Facts

You cannot grow sweet potatoes from regular potatoes—they're botanically unrelated plants. Sweet potatoes (Ipomoea batatas) grow from slips sprouted from mature sweet potatoes, while regular potatoes (Solanum tuberosum) are entirely different tubers.

Why Growing Sweet Potatoes from Regular Potatoes Doesn't Work

Many gardeners mistakenly believe they can grow sweet potatoes using regular white potatoes. This fundamental misunderstanding stems from the similar-sounding names, but sweet potatoes and regular potatoes belong to completely different plant families. Attempting to plant a regular potato expecting sweet potatoes will only yield regular potatoes—or nothing at all if conditions aren't right for potato growth.

Understanding this distinction is crucial before starting your gardening project. Let's clarify the botanical realities and provide accurate growing methods.

Botanical Differences: Sweet Potatoes vs. Regular Potatoes

Characteristic	Sweet Potatoes	Regular Potatoes
Scientific Name	Ipomoea batatas	Solanum tuberosum
Plant Family	Convolvulaceae (Morning Glory)	Solanaceae (Nightshade)
Edible Part	Storage root	Tuber (modified stem)
Growing Season	100-170 frost-free days	70-120 days
Soil Temperature	65-85°F (18-29°C)	45-55°F (7-13°C)

This botanical distinction explains why planting a regular potato won't produce sweet potatoes. The USDA Agricultural Research Service confirms these plants have no genetic relationship despite both being called "potatoes"—a historical naming convention that continues to confuse gardeners.

How to Actually Grow Sweet Potatoes: A Step-by-Step Guide

Now that we've clarified the misconception, here's how to successfully grow sweet potatoes using the proper method:

Starting with Sweet Potato Slips (The Right Way)

Sweet potatoes grow from "slips"—sprouts that develop from mature sweet potatoes. Here's the proven process:

1. Select healthy sweet potatoes: Choose disease-free, firm sweet potatoes from the grocery store or nursery (avoid waxed varieties)
2. Sprout the potatoes: Place sweet potatoes in a jar of water (half-submerged) or in moist sand/vermiculite
3. Wait for slips to develop: After 3-4 weeks, vine-like slips will emerge (maintain temperatures above 70°F/21°C)
4. Remove slips: Gently twist slips from the potato when they reach 6-9 inches with several leaves
5. Root the slips: Place slips in water for 1-2 weeks until roots develop (change water every 2-3 days)

Planting Your Sweet Potato Slips

Timing and technique are critical for successful sweet potato cultivation:

• Planting time: Wait until soil reaches at least 65°F (18°C) and all danger of frost has passed—typically 3-4 weeks after your last spring frost date
• Soil preparation: Amend with compost but avoid excessive nitrogen which promotes vines over roots
• Planting depth: Bury slips 3-4 inches deep, leaving top leaves exposed
• Spacing: Plant 12-18 inches apart in rows 36-42 inches apart
• Watering: Water thoroughly after planting, then reduce to 1 inch per week once established

Sweet Potato Growing Timeline

Understanding the growth cycle helps manage expectations:

• Weeks 1-4: Slip development and rooting phase
• Weeks 5-8: Vine establishment and early root development
• Weeks 9-16: Critical tuber formation period (varies by variety)
• Weeks 17-20: Maturation phase (stop watering 2-3 weeks before harvest)
• Harvest: When leaves begin yellowing or before first frost (typically 100-170 days after planting)

The University of California Cooperative Extension notes that sweet potatoes require 100-170 frost-free days to mature properly, making them challenging to grow in cooler climates without season extension techniques.

Common Sweet Potato Growing Mistakes to Avoid

Even experienced gardeners make these errors when growing sweet potatoes:

• Planting too early: Cold soil below 60°F (15°C) stunts growth and invites rot
• Over-fertilizing: Excess nitrogen creates lush vines but small roots
• Watering inconsistently: Fluctuating moisture causes cracked or misshapen tubers
• Harvesting too early: Roots need full maturation for proper sweetness and storage
• Handling roughly after harvest: Cure roots at 85-95°F (29-35°C) with high humidity for 5-10 days before storage

Practical Tips for Successful Sweet Potato Harvests

Implement these evidence-based techniques for better results:

• Variety selection: Choose varieties suited to your climate (Beauregard for warm regions, Georgia Jet for shorter seasons)
• Soil warming: Use black plastic mulch to increase soil temperature in cooler climates
• Container growing: Use large pots (at least 15 gallons) with excellent drainage for limited-space gardening
• Pest management: Rotate crops annually to prevent sweet potato weevil infestations
• Storage: Keep cured roots in a cool (55-60°F/13-16°C), dark, humid place for 4-6 months

According to North Carolina State University's sweet potato research program, proper curing increases sweetness and storage life by converting starches to sugars and healing surface wounds.

Why This Misconception Persists

The confusion between sweet potatoes and regular potatoes stems from historical naming conventions. When sweet potatoes were introduced to Europe from the Americas, explorers called them "potatoes" due to superficial similarities. This linguistic overlap continues to cause gardening confusion today. Understanding the botanical reality prevents wasted gardening efforts and sets realistic expectations for successful cultivation.

Can I grow sweet potatoes from regular white potatoes?

No, you cannot grow sweet potatoes from regular potatoes. They are botanically unrelated plants from different plant families. Sweet potatoes belong to the morning glory family while regular potatoes are in the nightshade family.

How do I start growing sweet potatoes properly?

Sweet potatoes grow from slips (sprouts) developed from mature sweet potatoes. Place a sweet potato in water or moist medium until slips emerge, then remove and root the slips before planting in warm soil after the last frost.

How long does it take to grow sweet potatoes?

Most sweet potato varieties require 100-170 frost-free days to mature properly. The exact time depends on the variety and growing conditions, with warmer climates generally producing faster results.

Why are my sweet potato vines growing but not producing roots?

Excessive nitrogen fertilizer promotes vine growth at the expense of root development. Sweet potatoes need balanced soil with lower nitrogen content. Also ensure you're giving them enough warm growing time—roots develop primarily in the final 6-8 weeks before harvest.