How Sweet Potatoes Are Harvested

Ok, sweet potatoes aren’t harvested; they’re dug. But “How Sweet Potatoes Are Dug” just doesn’t quite sound grammatically correct, though it might be. And ‘dug’ is the past tense for dig, which is how one gets sweet potatoes out of the ground.

This kind of terminology is one of the things I’ve been introduced to as I’ve gotten to know sweet potato growers over the years. I don’t always pay attention to the fact that some of the lingo of East Texas farmers has snuck into my usual way of talking about them and with them, until someone asks me to clarify something.

So, sweet potatoes are dug. Not usually by hand if the grower can help it. There are machines for that, of course. On a small farm where only a few rows or a couple of acres have been planted, a grower can simply use a plow to turn up the dirt in the middle of the row, which exposes the potatoes.

Oh yeah. Uh, sweet potatoes grow on a vine and the potatoes develop underground, like a white potato does. They are related to the morning glory family. They are biologically different from a yam. No, really, they are. Sweet potatoes and yam (real yams) are from different plant families. See here. 

Ok…back to how the potatoes are dug. When growers plant many acres, like the folks I’ve known in East Texas, they have a digger and they “bar-off” the rows. First, the vines are mowed down just a bit. Then an attachment on a tractor is taken through the rows. It creates definite wide rows so the tractor driver knows where to place the plow to reach the potatoes.

The digger is basically a plow on a trailer that is pulled by a tractor. As the tractor goes along, the plow (sometimes there are two) at the front of the trailer digs into the soil and loosens the vine and the potatoes. Just up from the plow is a metal chain conveyor belt that is down at the level of the soil being loosened. As the potatoes are disturbed from the ground, they are carried up the conveyor belt to the main part of the trailer. Going up the conveyor the soil and vines fall through the metal chain belt. On the trailer are real people who sort the potatoes as they go by. One person picks out all the No. 1’s, another person the No. 2’s. Still another person will pick out the Jumbo’s. Often the grower will also collect potatoes that can be sold to the canneries. These “canners” are potatoes that aren’t pretty and aren’t necessarily small (sometimes they’re huge!), but they will make great canned sweet taters. You know, the kind that are sweetened and usually have some cinnamon added – candied yams, as they are sometimes called – though they aren’t really yams.

So, on the trailer stand the people picking out the potatoes as they go by. The potatoes are placed in large wooden crates that when full hold about 1,000lbs each. This is skilled labor, even if it doesn’t look like it. The different grades of potatoes – No. 1, No. 2 – have specific characteristics that are standardized in the industry. To be able to pick out potatoes with specific characteristics as they go by on a conveyor belt and be accurate takes skill.

In a good year, a grower will get 20,000/acre of potatoes. I think that is for No. 1’s and No.2’s together, but it’s been so long since I’ve talked to a farmer in a good year that I’ve forgotten. The growers I have worked with usually plant about 50-100 acres. Most often they own some portion of the land they plant on, but the majority of it is leased.

Once the potatoes are dug and placed in the wooded crates, the crates are put on a truck and taken to the potato house or potato barn (usually just a few miles away) where they are stored to cure. After a week or two of curing, the potatoes are washed and boxed for sale. The curing process – which is really just storing the potatoes in the right temperature and humidity range – thickens the skins slightly and allows the sugars in the potatoes to sweeten.

The potatoes going to the cannery are simply kept in the large wooden crates until the big trick comes to pick them up. There is a cool feature on the forklift that allows the crate to be lifted and then dumped into the open top of the truck. To do this, the forks on the forklift actually rotate.

So that’s how the potatoes are dug. It’s really a wonderful experience to see how all of it works. Farms like these are small businesses that may have an ancient truck that hauls the potatoes from the field to the barn, but they some great technology to help them along the way. You just never know, though, when your sweet potato grower also has a Master’s degree in Agribusiness, even though he tells you, “They’s a lot of potatoes out there!”