I enjoy sweet potatoes immensely. I didn’t eat them often growing up because I lived on a farm that grew the other kind of potato, the generic white-fleshed, brown-skinned version. Truth be told, I prefer the sweet potatoes. The reason why? To me, they just have more flavor. And the bonus is they are nutritious, being high in Vitamin A and fiber and having a low glycemic index compared to round whites.

Growing round white potatoes was a rite of passage for me in my gardening journey and I’ve grown them for many years. I have not yet gotten around to growing sweet potatoes. But that will change this year! What I love about sweet potatoes is that there are so many different varieties. We think of them as being orange, but there are so many different colors, textures and sweetness levels. The Japanese sweet potato, or Murasaki, is one of my favorite. The folks at Sow True Seed have a great assortment if you’d like to explore further.

When to Plant Sweet Potatoes

And it turns out that at this moment—the middle of May—I’m right in time to plant them, or nearly so. The end of May to the beginning of June is the best time to plant them here in New England. If you are located south of here, April may be a better time. Just be sure that all danger of frost is gone and that the soil temperature is consistently above 65F. That’s pretty warm, and that’s why sweet potatoes are typically grown in the South where soils warm up faster.

How to Plant Sweet Potatoes

Sweet and white potatoes both form tubers, but their method of planting are different. For white potatoes you cut a tuber in half, being sure each half has an “eye” or growing point. For sweet potatoes, you plant their “slips,” which are the skinny green plants that grow from the sweet potato tuber. Why couldn’t you just plant the tuber? I bet you could, but that would add extra growing time to your crop. This would delay your harvest, possibly pushing it beyond the date of the first frost.

Space these slips 12 to 18 inches apart in rows 3 feet apart to allow ample room for vine spreading. Insert each slip about 3 to 4 inches deep, so that most of the stem is in the ground and the leaves are sticking out above.

Soil & Sunlight Requirements

Sweet potatoes love the sun, so find a spot that receives 8 or more hours of direct sunlight. As for soil, a well-draining sandy loam soil with a nice dose of compost for added nutrition will do the trick.

Watering & Temperature

Water your slips in once you’ve planted and keep them well-watered for the first few weeks to enjoy they grow some good roots. As the plants develop, you’ll cut back on the water a bit, mainly to ensure the tubers are getting too wet and don’t start rotting underground. Again, they enjoy warm temperature and will grow best when its between 70-85F.

When to Harvest Sweet Potatoes

Sweet potatoes will be ready to harvest in about 3-4 months. If you plant them in June, you’ll likely start thinking about harvesting at the end of September. You’ll know they are ready when the begin to turn yellow. Dig them up using a garden fork to gently lift the tubers out of the ground.

Cure Your Sweet Potatoes!

Curing a sweet potato—essentially leaving it in a warm and humid environment for up to 10 days—does two things:

1. It gives the skin time to firm up and allows any minor harvesting wounds to heal, preparing it for long-term storage.
2. Curing converts the tuber’s starches to sugars, enhancing its sweetness and flavor.

Once the tubers are cured, they can be stored for up to six months. And if I was storing them at my place, they would not last more than three!