If you’re a gardener in the Pelican State, figuring out when to plant sweet potatoes in Louisiana is the first step to a fantastic harvest. Louisiana’s warm climate is practically perfect for these heat-loving tubers, but timing is everything to avoid those late frosts and ensure a long growing season.
This guide will walk you through the ideal planting windows, variety selection, and simple steps to grow your own delicious sweet potatoes right in your backyard.
When to Plant Sweet Potatoes in Louisiana
The prime time for planting sweet potatoes in Louisiana is from mid-April through early June. The soil temperature is the real key—it needs to be consistently above 65°F, and ideally closer to 70°F, before you put any slips in the ground.
Planting too early in cold, wet soil will stunt the plants or cause them to rot. A good rule of thumb is to plant about 3-4 weeks after your last average spring frost date. For most of Louisiana, the last frost falls in late February or March, making April a safe bet to start.
Understanding Louisiana’s Growing Zones
Louisiana spans USDA hardiness zones 8a to 9b. This means our growing season is long and hot, which sweet potatoes adore.
- North Louisiana (Zones 8a-8b): Aim for planting from late April to early May. Wait until the soil has truly warmed up.
- Central/South Louisiana (Zones 9a-9b): You can often start a bit earlier, from mid-April onward. Your frost-free period is longer.
Always check your local weather for a late cold snap, as Mother Nature can be unpredictable.
Choosing the Right Varieties for Louisiana
Selecting a variety that thrives in heat and humidity is crucial. Here are some excellent choices for our climate:
- Beauregard: The classic Louisiana favorite. It has a high yield, copper skin, and deep orange flesh that’s reliably sweet. It’s disease resistant and matures in about 90 days.
- Centennial: Similar to Beauregard and a top performer here. It’s a vigorous grower and produces well.
- O’Henry: A white-fleshed sweet potato with a creamy texture and slightly milder flavor. It stores very well.
- Vardaman: Sometimes called a “bush” type, it has shorter vines which is great for smaller gardens. The flesh is a beautiful orange.
Preparing Your Garden Bed
Sweet potatoes need loose, well-draining soil to form those nice, large tubers. Heavy clay soil will result in misshapen potatoes.
- Location: Choose a spot that gets full sun—at least 6-8 hours of direct sunlight daily.
- Soil Amendment: Work in several inches of compost or aged manure to improve drainage and fertility. Avoid high-nitrogen fertilizers, as they will promote leafy vine growth instead of tuber development.
- Mounding: Form raised rows or hills about 8-12 inches high. This improves drainage, warms the soil faster, and gives the tubers room to expand. Space rows about 3 feet apart.
Starting with Slips: Your Best Option
Sweet potatoes are grown from “slips,” which are small rooted sprouts from a mature sweet potato. You can buy them from local nurseries or online, or even start your own from organic sweet potatoes about 6-8 weeks before planting time.
The Step-by-Step Planting Process
- Planting Day: Choose a cloudy day or plant in the late afternoon to reduce transplant shock on the slips.
- Spacing: Plant slips 12-18 inches apart within your prepared row. The wider spacing gives you bigger potatoes.
- Planting Depth: Bury the slip deep enough to cover all the roots and about half of the stem. Sweet potatoes will root along the buried stem, which is a good thing.
- Watering In: Water thoroughly immediately after planting to settle the soil around the roots.
Caring for Your Growing Sweet Potatoes
Once established, sweet potatoes are relatively low-maintenance.
- Watering: Water deeply once a week if there’s no rain. They are drought-tolerant but produce best with consistent moisture. Reduce watering significantly during the last 3-4 weeks before harvest to allow the potatoes to cure on the vine and develop their sweetness.
- Weeding: Weed carefully early on. Once the vines spread and create a dense canopy, they will shade out most weeds on there own.
- Fertilizing: Go easy! A side dressing of a low-nitrogen, potassium-rich fertilizer (like a 5-10-10 blend) about a month after planting is usually sufficient. To much nitrogen gives you all vines and no potatoes.
Managing Pests and Problems
Louisiana’s humidity can bring some challenges.
- Sweet Potato Weevils: This is the most serious pest. Look for small, ant-like insects and larvae tunneling in vines and tubers. Use certified disease-free slips, practice crop rotation (don’t plant sweet potatoes in the same spot for 3-4 years), and destroy infected plants immediately.
- Fungal Diseases: Good drainage and air circulation help prevent root rot and other fungal issues. Avoid overwatering.
- Deer & Rabbits: They may munch on the tender vines. Fencing is the most effective deterrent.
Knowing When and How to Harvest
Your sweet potatoes are ready to harvest about 90-120 days after planting, typically from late August through October.
Signs of readiness include the leaves and vines starting to yellow. The best test is to gently dig around the base of a plant to check the size of a tuber or two.
- Use a garden fork, not a shovel, to carefully loosen the soil about 18 inches away from the main stem to avoid spearing the tubers.
- Lift the plant and gently sift through the soil with your hands to find all the potatoes.
- Handle them carefully, as the skin is very thin and easily bruised at harvest.
Curing and Storing Your Harvest
This step is non-negotiable for sweet potatoes grown in Louisiana or anywhere else! Curing heals minor wounds, toughens the skin, and converts starches to sugars, enhancing the flavor.
- Curing: Brush off excess dirt—do not wash them. Place them in a warm (80-85°F), humid place for 10-14 days. A shaded porch, garage, or a warm room with high humidity works well.
- Storing: After curing, store your sweet potatoes in a cool (55-60°F), dark, and well-ventilated place. Do not refrigerate them, as cold temperatures can damage their flavor and texture. Properly cured and stored, they can last for several months.
Frequently Asked Questions (FAQ)
Can I plant sweet potatoes from the grocery store?
You can try, but it’s not recommended. Store-bought potatoes are often treated with sprout inhibitors and may carry diseases. For best results, purchase certified disease-free slips from a reputable source.
How late is to late to plant sweet potatoes in Louisiana?
Planting after mid-June is risky. Sweet potatoes need a long, warm growing season. Late plantings may not size up properly before cooler fall temperatures arrive, which can stunt growth.
Can I grow sweet potatoes in containers?
Absolutely! Choose a large container (at least 20 gallons) with excellent drainage. Use a light, potting mix and follow the same care instructions. Bush-type varieties like Vardaman are ideal for this.
Why are my sweet potato vines huge but I have no potatoes?
This is almost always caused by excess nitrogen in the soil or over-fertilizing. It can also happen if you planted to early in cold soil. Next time, go easy on the fertilizer and wait for the soil to warm up fully.
What are good companion plants for sweet potatoes?
Good companions include bush beans, marigolds (to deter pests), and summer savory. Avoid planting squash or other sprawling vines too close, as they will compete for space.
By following these simple guidelines tailored to Louisiana’s unique climate, you’ll be well on your way to harvesting a bountiful crop of homegrown sweet potatoes. The key is patience—wait for that soil to warm up, give them plenty of sun and space, and they’ll reward you with a delicious, nutritious harvest come fall.