Sweet potatoes, also called yams in the United States, are related to the morning glory. They, like the Irish potato, came from Peru and Ecuador originally. Sweet potatoes are part of the root of the plant and each plant has between 4 and 10 eating-size potatoes.
Sweet Potatoes versus Yams
Although Southerners often call sweet potatoes yams, they are two separate vegetables. Sweet potatoes are grown commercially in the United States There are many commercial farms in East Texas that grow sweet potatoes each year. Yams grow in the Caribbean.
Planting Slips
Sweet potatoes are started from slips, much like onions. These slips are planted when the danger of frost is past, around April 15 for North Central Texas. Plant the slips 4-5 inches deep, covering several of the nodes on it. Space the slips 8-14 inches apart and leave 38-42 inches between rows.
Fertilization
You need to fertilize with a balanced fertilizer such as a 10-10-10. Apply half before you plant and work it into the soil, then apply the other half in a side dressing 3-4 weeks after planting. Do not put any fertilizer down within 60-80 days of harvest.
Watering
Sweet potatoes require a lot of water, especially when the slips are trying to get established. You should, however, stop irrigating 2-3 weeks before harvesting.
Harvesting
The proper time to harvest is when the foliage starts yellowing. Dig the potatoes up, being careful not to bruise them. If you bruise them, use them immediately. Trying to store bruised potatoes will rot them.
Curing the Potatoes
The sweet potato will ruin if it is left out in the sun after harvest. However, it needs to sit out in an area that is 85 degrees or so for about 7-10 days right after harvest to cure. After that, it can be packed in straw or newspaper and will keep 3-6 months. Freezing ruins the raw sweet potato, but it may be frozen after it is cooked.
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Great post on sweet potatoes! I always forget when I should harvest them but the yellowing leaves tip should help a lot.
Very helpful post, i always wanted to grom potatoes, thanks for the post.
Sweet potatoes are easy to grow in places with more than a 120-day growing season. They are usually grown in sandy soil, which makes them easier to dig, but they thrive in most soils, even heavy clays.
One of my favorite vegetables… Great post, thanks for the info!
Interesting post. We are growing sweet potatoes in containers and heavy clay. They are surviving extreme hot weather now.
Hi Stephanie:
Great post!
Good call on “lots of water” after setting the slips and trying to get it established. I also concur with the cessation of irrigation 2-3 weeks before harvesting. I do not have a lot of empirical data, but observations from experimental plots appear to show that withholding irrigation (assuming it does not rain) around this time frame also helps to set the skin and reduce bruising during harvest.
However, I would like to comment on your recommendation for 10-10-10 (N-P-K) fertilizer application. Evidence suggests that nitrogen (N) needs to be proportionally less relative to P and K. For example, a fertilizer analysis that shows 4-11-11 might be a better option. Depending on the actual rate that is applied, too much N can reduce adventitious root development and could negatively impact yield potential. The time frame for a side dress application (3-4 weeks after planting) is consistent with current evidence as regards optimum time for in-season application of N fertilizer.
Thanks!