How Long Do Sweet Potatoes Take to Grow? We Asked a Pro What Gardeners Should Expect

Key Points

Sweet potato maturity depends on the variety, ranging from about 100 days to over 120 days.

A key harvest signal is when the vegetables’ vine leaves start turning yellow.

Factors like the amount of sunlight and cold soil can affect growth times.

Potatoes can be a tricky vegetable to plant. Because they grow beneath the soil, it can be difficult to know when they’re ready to harvest.

Below, we asked a gardening expert everything you need to know about sweet potatoes, including different varieties, signs to help you determine harvest time, factors that affect growth time, and tips to help you grow the best sweet potatoes you can.

Meet the Expert

Lindsey Chastain is an expert gardener and founder of homesteading website The Waddle and Cluck.

How Long Does It Take to Grow Different Potato Varieties?

Sweet potatoes are often classified by their days to maturity from planting, also known as “days to harvest.” They’re usually divided into three categories: early, medium, and late.

An early potato will mature within 110 days, a medium type between 110 and 120 days, and a late type will take more than 120 days to mature. Sweet potatoes are also classified by their skin color – orange, white, or purple — which also determines their texture when cooked.

For example, orange skin lends itself to a soft and moist texture, while white flesh is typically firmer and drier.

“Sweet potatoes are pretty forgiving and a great entry point to growing on vines,” explains Lindsey Chastain, an expert gardener and founder of homesteading website The Waddle and Cluck.

Beauregard: This is the most common type of sweet potato, often found in grocery stores. It’s known for its red skin and orange flesh that’s soft and moist. They take around 95 days to reach harvest maturity.

Jewel: While also an orange sweet potato, Jewels are not as flavorful as Beauregards, but can still be used in all the same recipes, explains Chastain. They take between 100 and 105 days to grow.

Garnet: With dark red skin and orange flesh, this variety is sweeter and a little moister than Beauregards and is great mashed or roasted. They take around 105 days to mature. They need plenty of room for the vines to grow and a warm, humid growing season, says Chastain.

How to Know That Your Sweet Potatoes Are Ready for Harvest

Harvesting sweet potatoes is different from harvesting white potatoes.

“The plant doesn’t start to die back, so you should look for the leaves starting to yellow and the potatoes reaching the right size,” Chastain explains. “Don’t forget to look for soil bulging or mounding up around the base of where your potatoes are growing.”

She adds that you should always check the days to maturity for the variety, as that will be one of the most reliable indicators of harvest maturity. And, perhaps most importantly, all potatoes should be harvested before the first frost to prevent rot.

Factors That Affect Growth Time

Cold soil: Sweet potatoes thrive in warm soil. If the soil isn’t warm enough, it can slow growth and mess up harvest times. “Aim to have your growing season when your temperatures will consistently be above 70°F,” explains Chastain.

Dense soil: Sweet potatoes work best in loose, well-draining soil. This will allow their roots to expand without restriction, allowing for larger and well-shaped potatoes.

Not enough sunlight: Sweet potatoes are heat lovers and require between eight and 10 hours of direct sunlight every day. As tropical plants, they need high temperatures to trigger photosynthesis, which will maximize vine growth and ensure large and shapely tubers.

More Tips For Growing Sweet Potatoes

Sweet potatoes tend to grow best in raised beds, with loosely packed soil with good drainage, explains Chastain. She recommends avoiding fertilizers high in nitrogen.

“Too much nitrogen will make the vines grow like crazy, but the tubers will grow more slowly because all the energy is directed to the vines,” she explains.

It’s usually best practice to water your sweet potatoes regularly, but to taper off once you get closer to the harvest time.

Read the original article on The Spruce