When to Plant Sweet Potatoes – Perfect Time

Sweet potatoes are not only delicious but also incredibly nutritious, making them a favorite in many gardens across the country. If you’re looking to add this tasty root vegetable to your home garden, understanding when to plant sweet potatoes is crucial for a successful harvest. This guide will walk you through everything you need to know, from selecting the right time and conditions to planting, caring for, and harvesting sweet potatoes.

In this post, we’ll explore the best times to plant sweet potatoes based on your climate, the growing conditions they require, and how to ensure you’re setting them up for optimal growth.

1. Understanding Sweet Potatoes and Their Growing Requirements

Before diving into when to plant sweet potatoes, it’s essential to understand the plant itself and its unique growing needs. Unlike regular potatoes, sweet potatoes are part of the Convolvulaceae family and require a warmer growing season to thrive.

What Are Sweet Potatoes?

Sweet potatoes are often confused with yams, but they’re not the same. While both are root vegetables, yams are starchy and dry, whereas sweet potatoes are sweet, moist, and have a smoother texture when cooked. In terms of varieties, some of the most popular types of sweet potatoes include:

• Beauregard: A common variety with orange flesh and a smooth skin.
• Covington: Known for its high yield and sweet flavor.
• Jewel: A medium-sized variety with a rich, orange color.
• Centennial: A variety with a slightly firmer texture and darker skin.

These varieties all have slightly different growing habits and time frames, but they generally share the same basic growing requirements.

Sweet Potato Growing Conditions

Sweet potatoes are warm-weather crops, meaning they need warm soil, plenty of sunlight, and a long growing season to develop properly. Here are the key factors to consider:

• Soil Temperature: Sweet potatoes require a soil temperature between 65°F and 85°F (18°C to 29°C) to start growing. They will not thrive in cold soil.
• Soil Type: Loose, well-draining soil is best for sweet potatoes. Sandy loam with a pH level between 5.8 and 6.2 is ideal for optimal growth.
• Sunlight: Sweet potatoes need full sun, ideally around 6 hours of sunlight per day.
• Spacing: When planting sweet potato slips, space them about 12 inches apart in rows that are about 36 inches apart. Sweet potatoes are vining plants, so they need room to spread out.

2. Best Time to Plant Sweet Potatoes: Season & Temperature

The key to growing a healthy crop of sweet potatoes is planting them at the right time. Unlike cold-weather crops, sweet potatoes need consistently warm temperatures, which means the planting time is highly dependent on your climate.

Sweet Potato Growing Season

Sweet potatoes are typically planted in late spring to early summer, depending on your region. The growing season for sweet potatoes is about 90 to 170 days, meaning they need a long warm season to reach maturity.

If you live in a region with mild winters, you can plant sweet potatoes earlier in the spring. In colder climates, however, you’ll need to wait until the soil warms up properly.

How to Determine the Best Time to Plant Sweet Potatoes

1. Frost Dates: Sweet potatoes are sensitive to frost. Plant them after your last spring frost date has passed. You can check your region’s average frost dates through online gardening tools or your local agricultural extension office.
2. Soil Temperature: The most important factor for planting sweet potatoes is the soil temperature. The soil should consistently stay between 65°F and 85°F (18°C to 29°C). Use a soil thermometer to check the temperature before planting.

When to Plant Sweet Potatoes Based on Climate

• Southern Climates (Zones 8-11): These areas experience long, warm growing seasons, making them perfect for growing sweet potatoes. You can start planting as early as April or May in most cases.
• Northern Climates (Zones 4-7): In cooler regions, sweet potatoes may require a longer growing season. It’s best to plant after the last frost when the soil temperature has reached 65°F or higher—typically by mid to late May.
• Tropical and Subtropical Regions: These areas are ideal for year-round planting of sweet potatoes. However, even in these climates, spring is often the best time to plant for a bountiful summer harvest.

3. Step-by-Step Guide: How to Plant Sweet Potatoes

Once you’ve determined the best time to plant sweet potatoes, it’s time to get your hands dirty! Planting sweet potatoes involves several important steps to ensure they grow well.

Preparing the Soil for Planting

1. Clear the Area: Remove any weeds or grass from the area where you plan to plant. Sweet potatoes need a clean, weed-free space to grow.
2. Amend the Soil: Sweet potatoes prefer slightly acidic, well-draining soil. If your soil is heavy clay or compacted, amend it with organic matter such as compost to improve drainage.
3. Test the Soil pH: Sweet potatoes grow best in soil with a pH of 5.8 to 6.2. Use a soil testing kit to check the pH, and if needed, adjust it using lime (to raise pH) or sulfur (to lower pH).

Starting Sweet Potatoes from Slips

Sweet potatoes are commonly grown from slips, which are shoots that sprout from a mature sweet potato. To start slips:

• Step 1: Place sweet potatoes in a warm, sunny location (or in water, with the bottom submerged) and allow them to sprout. This takes about 4 to 6 weeks.
• Step 2: Once the slips are a few inches long, gently remove them from the sweet potato and allow the roots to form.

Note: You can buy sweet potato slips from nurseries if you prefer not to start them yourself.

Planting Sweet Potatoes

1. Plant Depth: Dig holes or trenches about 4 inches deep. Place the slips in the holes, ensuring the roots are well covered and the top of the slip is just above the soil surface.
2. Spacing: Space each slip 12 inches apart in rows that are 36 inches apart. This gives the plants enough room to spread and allows for good airflow.

Watering and Mulching

• Watering: After planting, water the slips thoroughly, but avoid overwatering. Sweet potatoes like consistently moist soil, but not soggy.
• Mulching: Add a layer of mulch around the plants to help retain moisture and suppress weeds. This is especially important if you’re growing sweet potatoes in an area with hot summers.

4. Regional Considerations for Planting Sweet Potatoes

Understanding your local climate is critical when deciding the best time to plant sweet potatoes. Certain regions have shorter growing seasons or cooler temperatures, so let’s dive into how to adjust your planting schedule based on your location.

Planting Sweet Potatoes in Cold Climates

If you live in a cold climate (USDA zones 4-6), you may have a shorter growing season. Here’s how to adjust:

• Start Indoors: Consider starting sweet potato slips indoors in early spring, which allows you to get a jump on the growing season.
• Use Row Covers or Cloches: To protect your plants from late frosts, consider using row covers or cloches that trap heat around the plants.
• Choose Shorter-Season Varieties: Some sweet potato varieties mature faster than others. Look for early-maturing varieties like Beauregard to ensure you can harvest before frost sets in.

Planting Sweet Potatoes in Containers

If you don’t have a garden or want to grow sweet potatoes in limited space, containers are a great option. Choose large containers with drainage holes and fill them with a loose, well-draining potting mix. When growing in containers:

• Use large pots or containers: Sweet potatoes need space to grow, so opt for large pots (at least 5 gallons or more).
• Provide adequate sunlight: Ensure your container is placed in a sunny spot for at least 6 hours per day.

5. Caring for Your Sweet Potatoes During the Growing Season

Once your sweet potatoes are planted, it’s time to focus on their care to ensure they grow healthy and produce a good harvest.

Watering and Fertilizing

Sweet potatoes need consistent moisture throughout their growing season. However, avoid overwatering, as sweet potatoes don’t like their roots sitting in water. Here’s what to consider:

• Watering: Water the plants deeply once a week, especially during dry spells.
• Fertilizing: Sweet potatoes are not heavy feeders, but a light application of balanced fertilizer in the early stages of growth can encourage strong root development.

Dealing with Common Pests and Diseases

Sweet potatoes are relatively pest-resistant, but they can still fall prey to certain pests and diseases, including:

• Sweet Potato Weevil: A common pest that can damage your sweet potato harvest.
• Wireworms: These pests attack young plants, so be sure to monitor for any signs of pest damage.

Common diseases include fusarium wilt and root rot, often caused by excessive moisture, so proper drainage is key.

FAQs

Can Sweet Potatoes Grow in Cold Weather?

Sweet potatoes are a warm-season crop that thrives in hot temperatures, typically between 65°F and 85°F (18°C to 29°C). Unfortunately, they cannot tolerate frost and cold weather can severely stunt their growth or kill the plants.

In cold climates, sweet potatoes need to be planted after the last frost and should not be exposed to frost during their growing season. If you live in an area with a shorter growing season or cooler temperatures, you can:

• Start sweet potato slips indoors: Begin the sprouting process early in pots or trays indoors and transplant them outdoors once the soil is warm enough (after the last frost).
• Use row covers: These can help keep the plants warm in early spring or late fall, protecting them from unexpected temperature drops.
• Grow in containers: If the weather is too cold outdoors, consider growing sweet potatoes in containers that can be moved to a warmer location when necessary.

Even though sweet potatoes prefer warm weather, with the right care and attention, they can be grown in colder climates as long as they are planted after the soil temperature is consistently warm.

How Long Do Sweet Potatoes Take to Grow?

The time it takes for sweet potatoes to mature depends on several factors, including the variety of sweet potato and the climate in which they’re grown. On average, sweet potatoes take between 90 and 170 days to grow from planting to harvest.

• Shorter-season varieties: Varieties like Beauregard may mature in around 90 to 120 days, while other varieties may take longer.
• Longer-season varieties: Some varieties, especially those grown in cooler climates, can take up to 150–170 days to fully mature.

In general, you can expect to harvest sweet potatoes in late summer or early fall, depending on when you plant them. One important indicator that sweet potatoes are ready to harvest is when the vines start to die back or turn yellow. However, the exact timing can vary based on growing conditions, temperature, and care.

What Are Sweet Potato Slips?

Sweet potato slips are small shoots or sprouts that grow from a mature sweet potato. They are the starting point for growing new plants and are the most common way to propagate sweet potatoes in home gardens.

How to Start Sweet Potato Slips:

1. Select a healthy, mature sweet potato: Use a sweet potato that is firm and free from any cuts or signs of rot.
2. Prepare the sweet potato: Place the sweet potato in a warm, sunny spot. If you’re starting indoors, you can place it in a shallow container of water with the bottom submerged, or simply place it directly in the soil.
3. Sprouting: In about 4-6 weeks, shoots will begin to emerge from the top of the sweet potato. These shoots are the slips.
4. Harvesting the slips: Once the slips are 6–8 inches tall, gently pull them from the sweet potato and allow the roots to develop in water for a few days or directly plant them in the soil.

Sweet potato slips can also be purchased from nurseries or garden centers if you don’t want to start them from scratch. They are a crucial step in growing sweet potatoes, as they are the vegetative propagation method used to grow new plants.

Conclusion

Planting sweet potatoes is an incredibly rewarding experience, and by knowing when to plant sweet potatoes, how to care for them, and when to harvest, you can enjoy a bountiful harvest.

Remember that the best time to plant sweet potatoes depends on your climate, soil temperature, and growing season. By following the guidelines in this post, you’ll be on your way to growing delicious, homegrown sweet potatoes that will be the highlight of your meals for months to come!