This is a springtime mistake that every year, most home gardeners fall into. At the nursery, you grab a packet of sweet potato slips; it’s labeled yam. Then you’re puzzled as to why they taste so bland and starchy at harvest time. Chances are, it had nothing to do with the quality of your soil, or even whether you watered well enough. It has more to do with choosing a variety intended for roasting (a moist dessert type) instead of one meant for mashing (a drier type, like a chestnut).
Knowing the details can be life-changing in how you grow, cook, and cure your sweet potatoes. They sorts into different texture families, and chart breaks down eight of the most common types. As you can see, no matter what their color, you’re going to have trouble guessing how something tastes by looking at its outer layer. For example, Garnet features a shocking burgundy-colored skin but inside is an orange-hued flesh that’s moist and ideal for use in casseroles. On the other hand, Japanese Purple has really dark purple skin but its flesh are quite dry and nutty, with excellent holding power when cut up into stir-fry chunks.
How to Grow Sweet Potatoes
The one major difference in cooking performance is dry versus moist. Bake the former, such as Okinawan, and you’ll be sorely disappointed if you hope for silky puree. Nope; the flesh doesn’t get soft. It is not bad. Great for when you want some structure in your dish, in the form of tempura, say, or roasted cubed bits.
It’s not just what you eat; it’s when. Because sweet potatoes are a warm-season crop, they don’t fare well in cold soil. They want a minimum of sixty-five degrees F, so plan to plant only after the soil warms up. I know it seems more logical to sow sooner then later. However, forcing things this way stunts the vines. Depending on which variety you grow, it can take anywhere from ninety-five days (for the early ones like Orleans or Beauregard) to 107 days (slower kinds such as Okinawan). That means if you choose a late variety and plan for a short season, you will likely end up with nothing when the frost arrives. Match the variety to your local weather window, says chart.
The magic comes next: curing. Once harvested, the roots will be raw and starchy. To fix that, they spend several days (maybe as long as a week) in a warm, humid location around eighty degrees Fahrenheit. During this time, the roots heals any slight injuries from harvest and convert their starches to sugars. If you don’t cure them, even a top-quality Beauregard won’t taste good. Cured, the sweetness intensifies big-time.
Small thing, but it matters. Why do most of us wash our potatoes immediately upon digging? Wrong move! Washing remove their natural protections and invites rot to set in. Brush or shake off excess dirt and let them dry. Then cure them. Later on, store them in a cool (fiftyish degrees Fahrenheit), dark spot. Do not ever refrigerate. Sweet potatoes turns mealy and hard as rocks overnight in the fridge.
And then there’s the matter of patience (partly a matter of yield), too. If you want reliable, high-yield choices, Covington and Jewel are commercial types that produce neat, uniform roots that stores well and pack easily. These is safe bets if you’re growing for a family dinner. If you want to experiment with cooking, try the purple ones. Their anthocyanins will add vivid color to whatever they’re in without any mushy collapse; they has an added nutty note that goes nicely with savory herbs instead of brown sugar.
At heart, sweet potatoes are vine crops, not tuber-y things at all, ultimately. They require full sun and well-drained soil (but it doesn’t have to be sandy; loamy soil is fine). Too much heavy nitrogen produces a lot of foliage but little in the way of roots (and then they’re just pencil-thin). Maintain fertility on the low side, and make your ridges high. Handle them carefully when you unearth them. Bruising leads to rot.
Choose a variety suited to your style of eating. And cure and stash them appropriately. Making good choices early in spring can mean the difference between a bland root and a fragrant, sweet side dish. What do you prefer? Do you prefer a roasted cube with some crunch to it, or perhaps the syrupy goodness of an old-fashioned candied yam? There’s a vine out there for you.
But rest assured: The best part of harvesting sweet potatoes happen after you bring the roots indoors and let them rest.