If you’re wondering when to plant sweet potatoes in Alabama, you’re in the right place. Getting the timing right is the single most important step for a great harvest in our state.
Sweet potatoes love warm soil and a long, hot growing season. Luckily, Alabama’s climate is perfect for them. Planting at the correct time ensures your plants avoid the last spring chill and have plenty of time to grow those tasty roots before fall.
When to Plant Sweet Potatoes in Alabama
For most of Alabama, the optimal planting window is from early May through mid-June. The soil must be warm—at least 65°F at a 4-inch depth—and all danger of frost must be long gone.
Here’s a more detailed regional breakdown:
- North Alabama: Aim for mid-May to early June. The soil warms up a bit slower here, so patience is key.
- Central Alabama: You can typically start a little earlier, from early May to early June.
- South Alabama: This region can often plant earliest, from late April through May, thanks to its warmer soils.
A good rule of thumb is to plant about 3-4 weeks after your last average spring frost date. If you plant to early, the slips will just sit there and could even rot in cool, damp ground.
Why Timing is So Critical
Planting to late is a common mistake. Sweet potatoes need 90 to 120 warm, frost-free days to reach a good size. If you plant in July, they won’t have enough time to mature before the first fall frost arrives.
Frost will damage the vines and can ruin the tubers in the ground. Your goal is to have them ready for harvest in early autumn, when the weather is still dry.
Understanding Your Planting Material: Slips
You don’t plant sweet potatoes from seeds, but from “slips.” These are the small sprouts that grow from a mature sweet potato. You can buy them from garden centers or mail-order nurseries, or you can grow your own.
If you’re ordering slips, time your order so they arrive within your optimal planting window. They are perishable and need to go in the ground quickly.
How to Grow Your Own Slips
- About 6-8 weeks before your planting date, get a healthy, organic sweet potato from the store or from last year’s harvest.
- Suspend it in a jar of water using toothpicks, with the bottom half submerged.
- Place it in a warm, sunny spot. Change the water weekly to keep it fresh.
- In a few weeks, sprouts (slips) will emerge from the top. When they are 6-10 inches long and have roots, gently twist them off.
- Place these slips in their own shallow water to develop stronger roots for about a week before planting.
Preparing Your Garden Bed
Sweet potatoes aren’t to picky about soil fertility, but they demand excellent drainage. They prefer a slightly acidic to neutral pH (5.8-6.2).
- Location: Choose the sunniest spot in your garden—at least 6-8 hours of direct sun daily.
- Soil: Loosen the soil deeply, as roots need room to expand. Raised beds or mounded rows are ideal for improving drainage and warming the soil faster.
- Fertilizer: Go easy on the nitrogen! Too much nitrogen gives you huge vines but small tubers. Use a balanced or low-nitrogen fertilizer at planting, or mix in compost.
Step-by-Step Planting Guide
- Plant on a cloudy day or in the evening to reduce transplant shock on the young slips.
- Space your slips 12 to 18 inches apart in the row, with rows 3 to 4 feet apart. They need space to spread.
- Plant them deep, burying the stem up to the first set of leaves. The buried nodes will form additional roots, leading to more potatoes.
- Water them in thoroughly after planting.
- Consider using black plastic mulch. It warms the soil, suppresses weeds, and conserves moisture—it’s a game-changer for sweet potatoes.
Caring for Your Growing Sweet Potatoes
Once established, sweet potatoes are relatively low-maintenance.
- Watering: Water consistently for the first few weeks. Once established, they are drought-tolerant, but a deep watering once a week during dry spells is best. Reduce watering in the final 3-4 weeks before harvest to prevent splitting.
- Weeding: Weed carefully early on. Once the vines spread and cover the ground, they will shade out most weeds.
- Feeding: Usually, no extra fertilizer is needed. If growth seems stunted mid-season, a side dressing of a low-nitrogen, potassium-rich fertilizer (like potash) can help.
- Pests: Watch for sweet potato weevils (a serious pest) and flea beetles. Crop rotation is your best defense against soil-borne pests.
When and How to Harvest
Your sweet potatoes are ready to harvest about 100-120 days after planting, usually from late September through October. A key sign is when the leaves and vines start to yellow.
- Use a garden fork to carefully loosen the soil about 18 inches away from the main stem to avoid spearing the tubers.
- Lift the cluster of potatoes gently.
- Handle them carefully, as the skin is very thin and easily bruised at harvest.
The Essential Step: Curing
This is non-negotiable for good storage! Curing heals wounds and converts starches to sugars, improving flavor and texture.
- Brush off excess soil—do not wash them.
- Place them in a warm (80-85°F), humid (85-90%) location for 10-14 days. A small space with a heater and a pan of water can work.
- After curing, store them in a cool (55-60°F), dark, well-ventilated place. Properly cured sweet potatoes can last for months.
FAQ: Sweet Potato Planting in Alabama
Can I plant sweet potatoes from the grocery store?
You can try, but it’s not always reliable. Store-bought potatoes are often treated with sprout inhibitors. For best results, use certified disease-free slips from a garden supplier or use organic potatoes to grow your own slips.
What is the best sweet potato variety for Alabama?
Beauregard is the top choice for home gardens here. It’s a reliable, high-yielding variety with good disease resistance that performs excellent in our climate. Other good options are Georgia Jet and Covington.
Is it to late to plant sweet potatoes in July?
In most of Alabama, yes, July is to late. The plants won’t have enough warm days to produce a meaningfull harvest before cool fall weather stops their growth. Stick to the May-June window.
How do I protect my sweet potatoes from weeds?
Black plastic mulch is the most effective method. It also warms the soil. You can also use organic mulch like straw, but apply it after the soil is already very warm.
By following this guide and paying close attention to timing, you’ll be on your way to a succesful harvest of homegrown sweet potatoes. There’s nothing quite like digging up your own bounty come fall.