Learn how to grow sweet potatoes in a no-dig garden for a bountiful harvest.
This post is a compilation of a lot of research and resources for growing sweet potatoes in a no-dig garden bed.
This post contains affiliate links, which means I make a small commission at no extra cost to you. See my full disclosure here.
My Experience Growing Sweet Potatoes in a No-Dig Garden
Update: I had an amazing first harvest last year and definitely plan to grow more sweet potatoes again this year.
I’m going to honest, I’ve never grown sweet potatoes before; which is a good reason I needed to do some research on how to grow sweet potatoes. I’m hoping to keep this post updated as I learn more and experience growing them myself.
Below is research I’ve gathered from books, videos and articles about the different methods for growing sweet potatoes. I hope you will find it helpful to you as you grow sweet potatoes this year too.
A Little Bit About Sweet Potatoes (and Yams)
Are sweet potatoes and yams the same? A quick google search will reveal that they are actually different plants. The way to distinguish between a sweet potato and yam is the skin texture. Sweet potatoes are smooth and yams are more rough like bark.
Most grocery stores don’t sell true yams. Even though they might be called yams they are actually just an orange sweet potatoes.
There are several varieties of sweet potatoes available; white, yellow, orange, red, brown and even purple. They are apart of the morning glory family of plants.
“How to Grow” Series
How To Grow Sweet Potatoes in a No-Dig Garden
Climate For Growing Sweet Potatoes
The best climate for growing sweet potatoes is in hot weather. July and August, with temperatures above 80 degrees, is the ideal time for them to grow. Although they can be grown in a less than ideal climate, it can affect the size of the harvest.
From panting to harvest it takes 100+ days for sweet potatoes to mature. Therefore it is important to get them in the ground long before July and August so they can do most of their growing during the hot summer months.
Propagate Sweet Potatoes
Sweet potatoes are grown by propagation. Although you can purchase propagated plants called slips, they can be rather expensive. Why not try and propagate them on your own?
One sweet potato can grow up to 50 slips. That’s a lot of sweet potato plants!
One tip I read is using small sweet potatoes for propagation typically produces more slip (or sprouting plants) than larger ones. Keep that in mind as you select your sweet potatoes for propagating.
How To Propagate Sweet Potatoes
Because it can take sweet potato slips awhile to get going, starting them in January is best.
First Step – Purchase some organic sweet potatoes from the grocery store. It is important that they are not treated with sprout inhibitors. Purchasing organic will make that less of a problem as they are typically not treated.
Second Step – There are two of ways to propagate sweet potatoes, in water or in soil.
- The water method – place the sweet potato in a jar of water suspended by tooth picks with pointy rooted end down. Make sure it’s the rooting end that submerged in water. It can be a little tricky to determine which end is the rooming end. Try and look for little roots coming off one end. Change water ever couple of days to keep it from getting gross. Keep in a warm sunny place.
- The soil method – fill a shallow pan with several inches of damp soil. Lay the sweet potatoes on their side and nestle into soil about half way. Keep in a warm sunny place making sure the soil stays damp especially as the slips begin to grow.
- ***Make sure to keep the plants warm or they will struggle to sprout. 75 degrees is an ideal temperature.
Third Step – Once the sweet potato slips are 6 inches long and have a decent amount of roots they will need to be separated from the parent root. To separate, gently pull the slips away from the parent root.
Forth Step – After separating plant the slips in pots if it’s still too cold for them to go in the soil outside. Anther option is to leave the slips attached to the parent root until the weather is warm enough for outdoor planting.
- Continue to keep the slips warm, around 75 degrees after separating.
Planting Slips Outdoors
Plant the slips outside 2 weeks after the last frost. But before planting slips out they need to be hardened off.
Hardening off plants means they need time to experience the outdoor climate before they are outdoors full time. Putting them outside for several days, a couple of hours at a time, should do the trick.
Sweet potatoes prefer soil that isn’t too rich in nutrients.
When planting, space the slips a least 1 foot apart and 2-3 inches deep.
Another method for growing sweet potatoes is in containers. Just make sure the container is at least 1 foot deep and keep well watered over the hot summer months.
Growing Into Sweet Potatoes
Sweet potato vines tend to grow all over the place. Try not to disturb the vines too much as that can decrease the harvest. Growing trailing sweet potato vines up trellises will save room in the garden.
I’ve read two conflicting views on watering throughout the summer. I’m going to experiment this year and see what works best. Below you can read the two conflicting views.
- Sweet potatoes can thrive in dry weather. This can actually help increase the harvest as well. (Source)
- Water sweet potatoes deeply especially during the hot dry months of summer. (Source)
Grow More Sweet Potatoes From Cuttings
Another way to increase your sweet potato harvest is to grow more plants from cuttings. After the vines are 3-4 feet long, cut 8 inches off. Plant the cutting horizontal leaving a few inches sticking out of the soil.
Keeping the cuttings well watered will allow it to sprout roots, therefore producing more sweet potatoes for a larger harvest!
**The leaves on the vines are edible and can be harvested in moderation over the summer months.
Harvesting Sweet Potatoes
The sweet potato roots grow fast in late summer and early autumn. Planting late or harvesting too early will lower the yield.
However, leaving them until there is a hard frost can jeopardize the harvest. If a hard frost kills the vines, dig the sweet potatoes up immediately.
Start checking sweet potatoes around 110 days after planting outdoors. If they look to be a good size, they are ready to start harvesting.
Pick a sunny day when the soil is dry to dig them up. Cut back all the vines at the base. Carefully dig about 18 inches from the plant to avoid spearing the sweet potatoes.
Try to disturb the soil as little as possible. It is impossible not to disturb the soil a little bit when digging up sweet potatoes.
There is no need to wash them before curing or storing. This will just increase the risk of damaging them and reduce the ability to store them for longer periods of time.
Next, lay the sweet potatoes in the sun for 2-3 hours before moving to the next step. (I’m not sure if this step is completely necessary as it wasn’t in all of the sources I researched).
Sweet potatoes do have the ability to heal if broken in half or nicked but bruised or speared sweet potatoes will rot. Damaged sweet potatoes won’t keep as well and should be used first.
Curing – Very Important Step
Although you can eat the sweet potatoes right away after harvesting, they will be starchy. Curing is need to give them their sweet flavor. They also must be cured for winter storage or they will spoil.
Curing sounds more complicated than it is. To cure sweet potatoes, keep them at 80-85 degrees in high humidity for 2 weeks. It is important that they don’t get too or too cold.
- Curing in a large plastic tote – cure sweet potatoes in a large plastic tote lightly covered with a lid or damp towels. Place in a small closet with an oil filled electric heater. Not the kind that blow hot air. That would be a fire hazard. Make sure the humidity stays around 80.
- Curing in a greenhouse – place sweet potatoes on a drying rack and cover with a blanket to keep the moisture in. Keep an eye on the temperature in the greenhouse so the sweet potatoes don’t get cooked.
- Curing inside in humidity chamber – to create humidity chamber use plastic bags and poke with holes to allow for some ventilation. Cure sweet potatoes in a sunny location to keep them warm, 80-85 degrees.
- Curing inside under a damp towel – cure the sweet potatoes in a warm place (next to a heat source like a wood burning stove). Cover with a damp towel to keep their environment humid. Once again keep temperatures around the 80 degree mark.
Storing Sweet Potatoes
After curing, it is important to store sweet potatoes properly for them to last a long time. They can last up to a year if stored well.
Update: we didn’t individually wrap our sweet potatoes but placed them in large paper bags. They have stored well in our basement.
Wrap your sweet potatoes individually in paper and store in a cool dark place with temperatures around 50-60 degrees.
The longer sweet potatoes are stored the sweeter they get. At least 6-8 weeks is optimal but they are edible anytime after harvesting.
Make sure to used damaged and small sweet potatoes first as they don’t keep as long.
Other ways to preserve sweet potatoes are through canning, freezing or drying.
Delicious Sweet Potato Recipe
This delicious sweet potato casserole recipe is a family favorite.
Sources For How To Grow Sweet Potatoes in a No-Dig Garden
Below are links to the sources used to gather all the information for this blog post.
Other Gardening Post
Subscribe for How to Grow Series
I’m also working on a How To Grow blog series were we will explore how to grow many different types of vegetables, fruit and herbs in the garden. Some I have had experience with growing and others I’m learning myself for the first time.
Please drop a comment below if you have any particular plants you’d like to learn how to grow and I’ll see if I can fit them into my series.