The Best Unusual Roots to Grow in Arkansas

For Arkansas, the best unusual roots are the ones that either relish a long hot summer or sit out a mild winter in the ground: sunchokes, horseradish, and unusual sweet potato types on the warm side, plus daikon, salsify, scorzonera and burdock sown for fall. Parsnips and celeriac are the gamble. Here is the reasoning, county by county caveats included.

The short answer for Arkansas

Choose by type, not by variety name. Heat-loving and perennial roots are the safest bets in Arkansas, and cool-season roots work best when you steer them into fall. The slowest, fussiest cool-season roots are the ones that struggle.

The numbers behind that advice come from NOAA’s 1991-2020 Climate Normals for a Little Rock station. The 32°F freeze dates fall from March 12 to March 28 in spring and from November 7 to November 20 in fall. Those are not deadlines. They mark the 30-70% probability band for a 32°F freeze, so a freeze after the later spring date, or before the earlier fall date, is still possible in any given year. Tender plants need the stricter 36°F light-frost dates from NWS Little Rock: April 3 in spring and October 31 in fall.

That gap matters. A gardener who treats March 28 as “safe” will put sweet potato slips or ginger out about a week ahead of the light-frost date, and those crops also want warm soil, which trails the calendar. For dated sowing windows by crop, see When to Plant Unusual Roots in Arkansas.

That 30.9°F figure is the mean daily minimum of the coldest month, not a record low. It says nights in January average just under freezing, which is mild enough for roots to overwinter under a layer of mulch but cold enough that tender types will not.

What will not work here

Spring-sown parsnips are the classic Arkansas letdown. The last 32°F freeze can come as early as March 12, so gardeners sow early, but the crop is slow enough that it is still working when summer heat arrives. Germination is already patchy, and roots that size up in hot weather tend to turn woody and strong-flavored. Celeriac has the same problem with a longer list of complaints.

Planting tender roots on the 32°F date is the second mistake. Between March 28 and the April 3 light-frost date there is a real chance of a cold snap, and ginger, turmeric and sweet potato slips do not forgive it. Sweet potato types also sulk in cold soil even without frost, so a cool wet April stalls them.

Fall planting has its own cliff. If the first light frost arrives October 31, any tender root still in the ground by then is finished, while the 32°F freeze may not come until November 7 to 20. Oca, a tuber that forms late as days shorten, often gets caught by exactly this gap. Unless you can protect it, count it as a stretch crop here, not a reliable one.

Humidity is the quiet killer. Arkansas summers are muggy, and tightly packed foliage stays damp. Close spacing that works in a dry western garden invites rot and leaf disease here. Give sweet potato vines and sunchoke stands room, and thin radish-family roots like daikon firmly, because crowding in warm, wet weather is how they split and rot.

Weekly deep watering fails in a different way. In a hot spell, a once-a-week soaking leaves the top few inches swinging between soggy and dry, and that is what cracks and forks roots. Even moisture, with mulch to hold it, beats a big weekly dose. Heavy clay, common in parts of the state, makes this worse by holding water in wet weeks and baking hard in dry ones. Raised rows or beds with loosened soil help every crop on this page.

One thing this page cannot do is rank individual cultivars. The facts it draws on cover climate, not variety trials, so it names types and examples rather than inventing a “best cultivar” list. County trial results, covered below, are the right place for that.

What changes across Arkansas

There is no single answer for the whole state. The USDA Plant Hardiness Zone Map (2023 edition, built on 1991-2020 normals) places Arkansas anywhere from 6b to 8a. That is four half-zone steps, and the system rests on one variable: the average annual extreme minimum temperature. It tells you what survives winter, not how long your growing season is.

The frost dates above belong to a Little Rock reference, so treat them as the middle of the state’s story. Other areas differ. A gardener in the northern tier or at altitude, in the Ozark hills for example, should expect a later spring and an earlier fall than those dates. That shrinks the window for slow warm-season crops like ginger and sweet potato, and it helps cool-season roots, because fall cools sooner and spring stays cooler longer. Shift tender plantings later and fall sowings earlier.

Toward the south of the state, the pattern runs the other way. Summers hold heat longer, so fall roots need a later start to avoid germinating in a heat wave, and winter-sown crops carry less risk. Warm-season crops have more room, but disease pressure from humidity rises with it.

Winter hardiness is a smaller worry across most of this range, but not zero. In the colder end, mulch heavily over horseradish crowns and anything you plan to leave in the ground, and expect the occasional winter to take tender perennials entirely.

Nobody should guess their own zone from this page. Look it up on the USDA map by ZIP code, then read the result against the spread here. For the broader picture of which roots suit the state, Growing Unusual Root Crops in Arkansas covers the full set.

Where to check this for your own county

Your state extension service is the next stop. In Arkansas that is the Cooperative Extension Service run through the University of Arkansas System Division of Agriculture, with an office in every county. Its agents see what actually grows in local soil, and they hear about failures that no national dataset records.

Look for two things. First, a local vegetable planting calendar, ideally one written for your county or region rather than the whole state. Second, any varieties trialled near you, since a cultivar that thrives in one corner of the state can disappoint in another. County Master Gardener programs often run demonstration beds, and their notes on sweet potatoes, sunchokes and fall root crops are worth more than any list from a distance.

A county recommendation beats a state one, and this page is the state one. It is built on a Little Rock station and a statewide hardiness range, which means it flatters the middle and misses the edges. The sources behind this page also do not include an Arkansas extension calendar for unusual roots. The calendars on file are lawn-care guides from another state, so they were left out rather than borrowed.

Bring your county name and a specific crop when you contact the office, and ask what dates they use for the light-frost threshold, not only the 32°F one. If their numbers differ from those here, trust theirs.

Checking this against your own garden

Your own observations outrank every date on this page. Three are worth watching, and none needs equipment.

• Soil warmth by feel. Push a hand a few inches into the bed in the morning. If it still feels cold and clammy, warm-season roots will sit idle. A bed that warms early, such as one near a south-facing wall, is a head start. A low, shaded patch that stays cool tells you to plant later there.
• The first male flowers. Squash and cucumbers send up male blooms before female ones. When they open in your yard, the season has truly warmed, which is a useful cue for planting heat-lovers. If neighbors’ flowers appear a week before yours, your spot runs cooler.
• The first true leaves. Seedlings show a pair of seed leaves, then the first real ones. Direct-sown roots that reach that stage cleanly are ready to thin. If they stall or never show, the soil was too cold, too hot or too crusted for your sowing date.

Keep notes for one season: the date you planted, the date those three signs appeared, and the date of your first light frost. Next year those notes will be a better calendar than any published window.

Common questions

Which unusual root is easiest to grow in Arkansas?

Sunchokes and horseradish are the least demanding. Both are perennial and winter-hardy here, since the coldest month’s mean minimum is 30.9°F. Plant them where you want them to stay, because both spread.

Can I grow parsnips in Arkansas?

You can try, but they are a gamble. They are slow and prefer a long cool season, and Arkansas heat arrives before spring-sown roots finish. Fall timing gives them a better shot.

Which frost date should I use for sweet potatoes and ginger?

The 36°F light-frost dates: April 3 in spring and October 31 in fall, from NWS Little Rock. The 32°F dates (March 12 to 28 and November 7 to 20) are too generous for tender plants.

Is Arkansas one hardiness zone?

No. The USDA Plant Hardiness Zone Map (2023) ranges from 6b to 8a across the state. Check the map for your own location and compare it with your county extension office’s advice.