When To Plant Sweet Potatoes In Mississippi

If you’re planning your garden in Mississippi, knowing when to plant sweet potatoes is the first step to a great harvest. This guide will walk you through the optimal planting season and everything you need to succeed.

Sweet potatoes are a perfect crop for our long, hot summers. They thrive in the heat and can produce a generous yield with a little know-how. Getting the timing right is crucial, as planting too early or too late can affect your crop’s growth and storage quality.

The single most important factor for sweet potato success is soil temperature. These tropical plants despise cold soil.

You should plant your sweet potato slips in Mississippi after the danger of frost has completely passed and the soil has warmed up thoroughly. For most of the state, the ideal planting window runs from early May through mid-June.

North Mississippi: Aim for planting from mid-May to early June. The soil warms a bit slower here.
Central Mississippi: You can often start a little earlier, from early May to mid-June.
South Mississippi: This region can typically plant earliest, from late April through early June.

A good rule of thumb is to wait until nighttime temperatures consistently stay above 55°F. The soil should be at least 65°F for good root development. If you plant into cold soil, the slips will just sit there and not grow, or they might even rot.

Why Timing Matters So Much

Planting at the right time ensures your sweet potatoes have enough long, hot days to develop large, healthy tubers. It also helps them mature properly before harvest, which is key for good curing and storage.

If you plant to late, say in July, the tubers won’t have enough time to size up before cooler fall weather arrives. This can lead to a disappointing harvest of smaller potatoes.

Understanding Your Growing Season

Sweet potatoes need a long, frost-free growing period—typically 90 to 120 days depending on the variety. Mississippi’s climate is generally very favorable for this.

Count backward from your area’s average first fall frost date. For example, if your first frost is around October 25th and you choose a 110-day variety, you’d want to get your slips in the ground by around July 7th at the absolute latest. But earlier within the May-June window is always better.

Preparing for Planting: Slips and Soil

You don’t plant sweet potatoes from seeds. Instead, you use “slips,” which are small rooted sprouts grown from a sweet potato.

Getting Your Slips Ready

You can buy slips from local nurseries or reputable online sellers. Or, you can grow your own from organic sweet potatoes purchased at the store. Here’s a quick way to do it:

About 6-8 weeks before your planting date, place a sweet potato in a jar of water (pointed end down).
Use toothpicks to suspend it so half is submerged.
Put it in a warm, sunny spot. Shoots will sprout from the top.
Once the shoots are 6-10 inches long, gently twist them off. They often have tiny roots already.
Place these shoots in water for a few days to develop stronger roots before planting.

Preparing the Perfect Garden Bed

Sweet potatoes prefer loose, well-drained soil. They will struggle in heavy, compacted clay.

Loosen the Soil: Till or dig your bed to a depth of at least 10 inches.
Amend with Compost: Mix in 2-3 inches of finished compost to improve drainage and fertility.
Create Mounds or Rows: Form raised rows or individual mounds about 8-10 inches high. This improves drainage and warms the soil faster.
Fertilizer Note: Use a low-nitrogen fertilizer. Too much nitrogen gives you beautiful vines but few potatoes. A 5-10-10 blend is a good choice.

Step-by-Step Planting Guide

Choose a Sunny Spot: Select a location that gets full sun all day long.
Plant on a Cloudy Day: If possible, plant in the late afternoon or on a cloudy day to reduce transplant shock.
Space Them Out: Plant slips 12-18 inches apart within the row. Space rows about 3-4 feet apart, as the vines will spread widely.
Plant Deeply: Bury the slip deep, so that only the top leaves are above the soil. This encourages root development along the buried stem.
Water Well: Give them a thorough watering immediately after planting to settle the soil.

Caring for Your Growing Sweet Potatoes

Sweet potatoes are relatively low-maintenance once established.

Watering

Water regularly for the first few weeks to help the slips establish. Once the vines begin to run, you can reduce watering. They are drought-tolerant, but for best tuber development, provide about 1 inch of water per week during dry spells. Stop watering about 3-4 weeks before harvest to allow the potatoes to mature.

Weeding

Weed carefully early in the season. Once the vines spread and cover the ground, they will shade out most weeds. Avoid deep hoeing later on, as you might damage the shallow feeder roots and developing tubers near the surface.

When to Avoid Fertilizing

As mentioned, avoid high-nitrogen fertilizers. If your plants look to yellow and stunted mid-season, a side dressing of a low-nitrogen, potassium-rich fertilizer can help. But often, if you prepared your soil well, extra fertilizer isn’t needed.

Harvesting and Curing Your Crop

Knowing when to harvest is as important as knowing when to plant.

Signs of Readiness

The vines may begin to yellow slightly.
You’ve reached the days-to-maturity for your variety (check your slip tag).
The best test: gently dig around the base of a plant to check the size of a tuber or two.

In Mississippi, harvest typically occurs from late September through October, but always before the first frost. A light frost can damage the vines, but a hard freeze can harm the tubers in the ground.

How to Harvest

Use a digging fork, not a shovel, to carefully loosen the soil about 18 inches away from the main stem.
Lift the cluster of potatoes gently to avoid bruising or piercing them.
Shake off excess soil; do not wash them.

The Critical Curing Process

This step is non-negotiable for sweet potatoes that will store well. Curing heals minor wounds and converts starches to sugars, improving flavor and texture.

Place the unwashed potatoes in a warm (80-85°F), humid (85-90% humidity) place for 10-14 days. A small room with a space heater and humidifier works well.
After curing, store them in a cool (55-60°F), dry, and dark place with good ventilation. Properly cured sweet potatoes can last for many months.

Common Varieties for Mississippi Gardens

Choosing a well-suited variety can make your gardening easier. Some reliable choices include:

Beauregard: The most common variety, known for its high yield and good disease resistance. It has copper skin and orange flesh.
Georgia Jet: A fast-maturing variety (90 days) with red skin and orange flesh. Good for areas with a slightly shorter season.
Centennial: Similar to Beauregard and performs very well in the South.
O’Henry: A white-fleshed variety with a drier, creamier texture that some folks prefer.

FAQ: Sweet Potato Planting in Mississippi

Can I plant sweet potatoes in July?

It’s not ideal. Planting in early July may not give the tubers enough time to reach full size before cooler weather, especially for longer-season varieties. If you must plant in July, choose a fast-maturing type like ‘Georgia Jet’.

What is the best month to plant sweet potatoes?

For nearly all of Mississippi, May is the best month to plant sweet potatoes. The soil is warm, the weather is settled, and it gives the plants the longest possible growing season.

How do I protect young slips from late cold snaps?

If an unexpected cool night is forecasted after you’ve planted, you can cover your rows with floating row cover or even old blankets. Remove the covers during the day so the soil continues to warm up.

Why are my sweet potato vines huge but I have no potatoes?

This is almost always caused by too much nitrogen in the soil. This can come from over-fertilizing or planting in soil recently used for heavy feeders like corn or tomatoes. Next time, use a low-nitrogen fertilizer and avoid over-watering.

Can I save my own slips for next year?

Yes, you can. Save a few healthy, medium-sized potatoes from your harvest to produce slips next spring. This is a great way to save money and continue a variety that does well in your specific garden conditions.

Following this guide for the optimal planting season will set you up for a succesful and bountiful sweet potato harvest. With the right timing and simple care, you’ll be enjoying your own homegrown sweet potatoes for month’s to come.