Fruit Trees for Le Mars, Sioux Center and Orange City, Iowa

On February 11, 1988, the Hawarden station down on the Big Sioux read −33°F, while Sioux Center 2 SE, 170 ft higher, read −25°F and Le Mars −23°F. That's a 10°F spread across about 20 miles of northwest Iowa on one morning, and it's why choosing fruit trees for Le Mars, Sioux Center and Orange City starts with where your ground sits: in a river bottom, or up on the slopes and the spine.

The map covers the northwest Iowa end of Siouxland: Sioux County, north Plymouth County around Le Mars, Remsen and Merrill, Sheldon and Marcus on the east edge, and Hudson and Fairview across the Big Sioux in South Dakota. Type your address in the box on the map to get the number for your own place, and the list of what we sell that has come through it.

How to read this map

Every number is a 30-year planning low, the same number our cold hardiness calculator uses, built from NOAA station records since the 1995-96 winter and adjusted for the lay of the land. It's a safe number to plan on, not the record. You also get the MFTC zone (that number in half zones), the typical winter (an average year's coldest night, the kind of number USDA's zones are built on, which is why theirs read warmer) and a spring layer: how much warmer or colder a spot runs than Le Mars on a still, clear night at bloom.

Le Mars, the reference town, plans for −31°F (MFTC zone 3b) with a typical winter of −18°F. The middle of the growing ground is the same −31°F, and nine tenths of it falls between −33°F and −29°F. The warm end is the two big towns up on the high ground, Orange City and Sioux Center, both at −28°F (zone 4a). The cold end is the river bottoms up north, Rock Valley at −33°F and Fairview, South Dakota, at −35°F (zone 3a). The spring layer spreads wider, from 4°F colder than Le Mars at Brunsville to 5°F warmer at Lebanon.

Why the map looks the way it does

This is the Northwest Iowa Loess Prairies, the highest and driest part of the Western Corn Belt Plains: rolling loess upland, treeless except along the creeks and around farm groves. A low north-south ridge, the "spine," runs near Sioux Center. East of it the land drains to the Floyd River and its West Branch, west of it to the Rock and the Big Sioux. The upland towns sit at about 1,440 to 1,470 ft, the river towns about 200 ft lower: Le Mars at 1,231 ft, Rock Valley at 1,247 ft, Hawarden at 1,181 ft. On a clear, calm night the ground loses its heat to the sky, the air against it chills and gets heavy, and it slides down the draws into those bottoms and pools.

So the bottoms are the cold ground, and they get colder to the north. Along the Big Sioux the floor plans for −31°F around Hawarden, −33°F around Hudson and −35°F at Fairview. Just north of the map the Canton station, on the same river, holds the area's coldest NOAA reading, −47°F on February 2, 1905, and Canton was the coldest station, or tied for it, in 9 of the 12 biggest outbreaks here. The Rock River floor at Rock Valley plans for −33°F, the Floyd floor at Hospers −33°F. On January 12, 1912 the old Alton station on the Floyd read −42°F while Le Mars and Sioux Center 2 SE read −37°F. A river doesn't warm its bottom on a winter night; it's still the lowest ground.

The warmest ground is up high, and the warmest of that is in town. Orange City and Sioux Center sit 80 to 90 ft above their nearest low ground and both plan for −28°F, against −31°F for the floor within 3 miles of each. They're also the biggest towns up there, and on our map built-up ground can run up to 2.5°F warmer, since pavement and brick hold the day's heat and buildings hide the sky. Height alone isn't enough, though. The flat upland away from town (Granville, Perkins, Boyden) sits 20 to 70 ft above its low spots on slopes under 2 percent, plans for −30°F to −32°F and reads about even with Le Mars at bloom. On ground that flat the night's cold is made right where it sits and has nowhere to go.

The ground that shines at bloom is the slope breaks, where the upland falls toward a valley and the cold keeps moving past and out below. Lebanon (60 ft above its floor), Ireton (70 ft) and Crathorne (100 ft) run 4°F to 5°F warmer than Le Mars on a still bloom night. That's the thermal belt, out of the pool and below the windswept tops; Utah State's extension people say ground 50 to 100 ft above the valley floor is less freeze prone.

The north end runs colder on the whole. The Sheldon station has the coldest average winter low on the map, −21°F against −18°F at Le Mars (the Sheldon airport's is −20°F), and Ritter, Matlock and Boyden all plan for −32°F. Snow is likely part of it: Sheldon gets about 41 inches a year to Le Mars's 31, and air over lasting snow runs colder because the snow cuts it off from the ground's heat. On any one night the pattern can flip. The 1988 morning had Le Mars 10°F warmer than Hawarden; on January 19, 1970 Le Mars was the cold one at −35°F, with Hawarden at −28°F. Which valley wins depends on where the wind dies first and where the fresh snow lies, and over the long run no two long-record stations here differ by 3°F or more in the median coldest night of the year.

There's no big water to soften anything. Wind is the bigger player: open upland loses its snow, and bare frozen ground is what kills roots. The May 12, 2022 derecho brought straight-line winds of 50 to 70 mph across N'West Iowa, and a black wall of dust off bare fields rolled over Sioux Center.

Le Mars, Remsen and the Floyd bottom

Le Mars sits on nearly flat Floyd River floor at 1,231 ft, 30 ft above the lowest ground around it. It plans for −31°F (zone 3b), typical winter −18°F; the floor within 3 miles is −32°F (coldest tenth also −32°F) and the slopes and benches above it −29°F. Oddly for a valley town, the Le Mars station has the longest frost-free season on the map, 160 days. It's listed at 1,299 ft, some 60 to 70 ft above downtown, so it may sit up off the bottom; we don't know its exact site.

West Le Mars, 3 miles west on a toe slope 30 ft up, plans for −31°F (zone 3b) and reads even with Le Mars at bloom. The low spots run colder in spring. Brunsville, on river-bottom ground 5 miles west, reads 4°F colder than Le Mars, the worst spring reading of any named place on the map, and Merrill, 6 miles down the Floyd where the West Branch comes in, reads 1°F colder. East of town, Remsen and Oyens plan for −32°F (zone 3b). O'Leary, on the south upland 60 ft above its floor, is a warm spot at −29°F (zone 4a).

For a Le Mars lot, plant to −31°F: Haralson (−45°F) and Honeycrisp (−45°F) apples, Ure pear (−40°F), Toka plum (−45°F) to pollenize Superior (−35°F), and Meteor tart cherry (−40°F). Lapins sweet cherry (−35°F) clears the number but blooms early, so give it your highest corner. Keep apricots and peaches off the bottom; on the slopes above town, Westcot apricot (−45°F) is a fair bet. In Sioux City, the Sioux City map covers you.

Sioux Center, Orange City and the spine

Sioux Center sits right on the spine at 1,459 ft, on ground so gentle the section-line roads don't bend for its hills. It plans for −28°F (zone 4a), typical winter −16°F, and reads 3°F warmer than Le Mars at bloom; the Dordt University campus reads the same −28°F. The Sioux Center 2 SE station, 2 miles southeast and about 100 ft lower than downtown, has a 30-year number of −30°F. Orange City, the Sioux County seat, founded about 1870 by Dutch settlers from Pella, is the warmest named place on the map, just ahead of Sioux Center: −28°F (zone 4a), typical winter −15°F, 3°F warmer than Le Mars at bloom. The Orange City airport station has the mildest record on the map, an average winter low of −16°F, though it has only 20 winters on file.

Step off the high ground and it changes fast: Alton, 2.8 miles east of Orange City on the Floyd, plans for −32°F (zone 3b) and reads 2°F colder than Le Mars at bloom, 4°F colder than Orange City in winter and 5°F colder at bloom. Carnes, on the lowest ground south of Orange City, and Struble, down the West Branch Floyd, read the same: −32°F and 2°F colder at bloom. Maurice, on a toe slope 40 ft above its floor beside the West Branch, plans for −31°F (zone 3b) and reads 1°F warmer.

In Sioux Center or Orange City you can add Zestar!® (−40°F), Cortland (−40°F) and Liberty (−30°F) apples, Summercrisp pear (−40°F), Italian plum (−35°F), Lapins and Gold (−35°F) sweet cherries, Westcot and Sungold (−40°F) apricots, and Siberian C (−35°F) and Contender (−30°F) peaches. Contender, which Tom McCamant grows at Forbidden Fruit in Paradise, Montana, is the only commercial peach we know of that has taken −32°F. Blushingstar (−25°F) is worth a try against a south wall; it came through −25°F at our place on January 13, 2024. At Alton, Carnes and Struble, stick with trees rated −35°F and colder and leave apricots to the hill.

Sheldon, Hull and the north end

The Floyd rises near Sanborn and runs southwest past Sheldon and Hospers. Sheldon sits at 1,426 ft on a toe slope 50 ft above its local floor: −32°F (zone 3b), typical winter −21°F, yet 2°F warmer than Le Mars at bloom thanks to the slope. The floor within 3 miles plans for −33°F (coldest tenth −34°F), and there's no real bench ground. The Sheldon station has the shortest season here, 146 frost-free days. Hospers, 8 miles down the Floyd and 10 ft above the floor, plans for −32°F and reads 1°F colder at bloom. Hull (1,438 ft) plans for −31°F and reads 1°F warmer; Boyden, near the head of the West Branch, plans for −32°F and reads even. Marcus, the highest town on the map at 1,468 ft, and Granville plan for −30°F, just on the 3b side.

Plant the north end to −33°F: Haralson, Frostbite (−45°F), Wolf River (−45°F) and Snowsweet® (−45°F) apples, Kerr applecrab (−50°F), Luscious pear (−40°F), Toka with Pipestone (−40°F) plum, and Evan's Bali tart cherry (−45°F). Westcot apricot belongs on Sheldon's slope, not the Floyd flats. East of Marcus, the Spencer, Spirit Lake and Okoboji map takes over.

Rock Valley, Hawarden and the Big Sioux

The Rock River comes down from Minnesota through Rock Valley and joins the Big Sioux about 6 miles north of Hawarden. Rock Valley sits on its floor at 1,247 ft: −33°F (zone 3b), typical winter −20°F, 1°F colder than Le Mars at bloom. The floor around it runs −33°F to −34°F and the slopes up out of the valley −31°F. Across the Big Sioux, Hudson plans for −32°F and Fairview −35°F (zone 3a), typical winter −23°F; even the slopes around Fairview only reach −33°F.

Hawarden sits down at 1,181 ft on the Big Sioux, yet plans for −30°F (zone 4a), typical winter −17°F, 1°F warmer than the floor around it, partly from town heat. It still reads 1°F colder than Le Mars at bloom, and its station's median last 32°F, May 2, comes four days after Le Mars's. Hawarden Junction, 2 miles southeast on a 7 percent hillside 60 ft above the floor, plans for −30°F and reads 3°F warmer than Le Mars at bloom, a 4°F swing from downtown. At Oak Grove State Park, 4.5 miles north, the boat access sits on a steep toe slope 20 ft above the floor: −31°F, 1°F colder at bloom. Up to 40 deer a day winter in that park, so fence what you plant near the river.

A Hawarden town lot can take the Le Mars list plus Liberty and Contender; save apricots for the hillside. Farther up the Big Sioux, the Sioux Falls map takes over.

Ireton, Lebanon, Crathorne and the west-side slopes

West of the spine, between the West Branch and the Big Sioux, the upland breaks into slopes, and the hamlets there hold the best bloom-night readings of any named places on the map. Lebanon, 60 ft above its floor, plans for −31°F (zone 3b) and reads 5°F warmer than Le Mars at bloom. Ireton (1,421 ft, 70 ft up) plans for −31°F (zone 3b) and reads 4°F warmer, with the floor around it at −32°F. Crathorne, on a bench 100 ft up, plans for −30°F (zone 4a) and reads 4°F warmer; Highland Park (100 ft up on a 5.8 percent slope) and Mammen (80 ft up) plan for −30°F and read 3°F warmer, Highland Park in zone 4a and Mammen just on the 3b side.

Don't trust the hamlet name over your own spot: Craig sits 40 ft up a toe slope and still reads 2°F colder than Le Mars at bloom. Bob Purvis's rule fits this country. Plant on the slope, not the windswept top and not the bottom; an east-facing slope is ideal, because it warms quickly on a frosty spring morning and stays cooler on hot afternoons. Montana State's 4 to 8 percent grade is about what Mammen and Highland Park have.

This is where the early bloomers go. Westcot, Debbie's Gold (−50°F) and Sungold apricots, Lapins and Gold sweet cherries, Toka and Superior plums and Siberian C peach all clear the number on these slopes. Contender (−30°F) fits Crathorne and Highland Park and is worth a try at Lebanon.

Spring frost and bloom in Siouxland's north end

The spring layer follows the winter drainage, only stronger, because it's the still, clear-night pattern at full strength. The low spots (Brunsville, Carnes, Struble, Alton) read 2°F to 4°F colder than Le Mars, the slope breaks and Orange City 3°F to 5°F warmer. In a windy freeze the pattern flattens and the warm slopes won't be warm. With no big lake to hold bloom back, trees bloom with the first warm spell, and April swings hard: a Sioux Center forecaster called a 61°F Saturday before an 8-inch Easter blizzard normal for April.

Frost dates from NOAA station records, 1991 to 2020 medians (last 32°F in spring, last 28°F, first 32°F in fall, frost-free days, and the late last 32°F that comes 1 year in 10):

• Le Mars: April 28, April 14, October 4, 160 days, May 14.
• Canton, just north on the Big Sioux: April 30, April 21, October 4, 154 days, May 12.
• Sioux Center 2 SE: May 1, April 18, September 29, 152 days, May 15.
• Hawarden: May 2, April 20, October 4, 154 days, May 15.
• Sheldon: May 4, April 28, September 24, 146 days, May 20.

Michigan State's fruit people say open blossoms of nearly every tree fruit start dying at about 28°F, and Sheldon's median last 28°F comes two weeks after Le Mars's. Orange City's Tulip Festival makes a good yardstick. The bulbs are picked to peak the third week of May, yet some years they bloom near Memorial Day and others too early, and in 1982 late frosts browned the leaf tips as they came up. One year in 10 the last 32°F at Sioux Center 2 SE comes May 15 or later, right up against festival week. Just north of the map, Arlington Orchard near Rock Rapids had small crops for years from untimely frosts, and in one frost-free year gale-force winds stripped the blooms.

Site comes first; the FAO's frost protection manual calls it "the single most important method of frost protection." Put apricots, peaches and sweet cherries on the highest slope ground, apples and haskap (honeyberry) lower. Minnesota's fruit people say only about 15 percent of apple blossoms need to set for a crop. Fully open haskap flowers take 19°F. Unless the fruit is clustered (cherries, grapes), most fruit can lose half its blossoms with little effect. Through bloom, mow short, don't till, and water a day or two before a forecast frost, since firm, moist soil gives heat back at night.

What the weather records say

The coldest readings in NOAA station records here: Canton −47°F (February 2, 1905), Inwood 2 SW just north of the map −46°F (January 12, 1912), Alton −42°F (January 12, 1912), Le Mars and Sioux Center 2 SE −37°F (January 12, 1912), Sheldon −35°F (February 2, 1905) and Hawarden −33°F (February 11, 1988). Big outbreaks since include February 28, 1962 (Canton −36°F, Le Mars −34°F, Sioux Center 2 SE −27°F).

The average yearly low over each station's whole record runs −21°F to −22°F at Le Mars, Sioux Center 2 SE, Sheldon and Hawarden, and −24°F at Canton. USDA's 2023 zones are built on that kind of average; ours are built on the bad night. NOAA station records show the worst night in about 30 winters runs a median 13°F below a station's average winter low, and Le Mars shows exactly that: a typical winter of −18°F and a planning low of −31°F. So our zone usually reads more than a full zone colder than USDA's.

What you can grow here

Town lots, the spine, the west-side slopes and the south upland: −28°F to −30°F

Orange City, Sioux Center, O'Leary, Crathorne, Highland Park, Mammen and Hawarden.Apples: Honeycrisp, Haralson, Zestar!®, Cortland and Liberty. Pears: Ure, Summercrisp and Bartlett (−35°F). Plums: Toka, Superior and Italian. Cherries: Lapins, Gold and Meteor. Apricots: Westcot and Sungold, on the slopes and the spine towns. Peaches: Siberian C and Contender, with Blushingstar worth a try on a south wall. Grapes: Marquette (−35°F) and Brianna (−40°F).

The valley floors, the north end and most farm ground: −31°F to −33°F

Le Mars, West Le Mars, Merrill, Remsen, Alton, Hull, Sheldon, Hospers, Rock Valley and Hudson. Apples: Haralson, Honeycrisp, Frostbite, Snowsweet®, Sweet Sixteen (−40°F) and Zestar!®, plus Kerr and Centennial (−50°F) applecrabs; Ed Schultz saw zero winter injury on Centennial after a −47°F winter. Pears: Ure, Luscious and Flemish Beauty (−40°F). Plums: Toka, Pipestone and Superior. Cherries: Evan's Bali and Meteor. Grapes: Frontenac (−35°F), La Crescent (−40°F) and Valiant (−50°F). Liberty and Contender are worth a try at the warm end of this band, out of the draws.

The cold bottoms: −34°F to −35°F

Fairview, the Rock floor and the Sheldon flats. Apples: Wealthy, Oriole and Prairie Sensation (all −50°F) and Trailman applecrab (−60°F). Pears: Bolshaya and Krasnobokaya (−50°F). Plums: Brookred and Northern Blue (−50°F). Cherries: Evan's Bali and Romeo (−50°F). No apricots, peaches or sweet cherries down here.

Berries fit anywhere on the map: honeyberry (−50°F), Montana Black Currant (−50°F), Red Lake currant (−40°F), Boyne raspberry (−40°F), aronia (−50°F) and Honeoye strawberry (−50°F). Apples and plums need a pollenizer blooming alongside (Toka pollenizes Superior); our pollination maps sort out the pairs.

Roots are the weak link, and snow protects them; at Ed Schultz's farm in Gallatin Gateway, Montana, Bud 118 rootstock has seen near −50°F under snow without damage. Shelter open upland with a windbreak on the north and west, at least as tall as the trees and 40 to 60 percent dense, but don't run a solid one across the low side of a slope, where it dams cold air into the trees above it. Many farm windbreaks planted 20 to 40 years ago are mostly ash, now dying to emerald ash borer, so plan the replacements with the orchard in mind. Taper water from mid-August so trees harden off, but don't send them into winter bone dry; Altena Apples near Orange City hand-watered about 1,000 gallons through one dry fall to carry its trees into winter. The upland soil is silty clay loam in loess. Test drainage (dig 2 ft, fill, let it drain, refill: under 10 hours is well drained), and stay off flood ground on the Floyd and the Big Sioux.

Local troubles: fire blight worries Iowa growers, codling moth is here (Arlington Orchard traps it with a molasses lure), Honeycrisp gets bitter pit (growers spray calcium yearly), birds peck ripe apples, deer browse hard near the river, and hail and derechos come through.

Fruit history in Sioux County and Le Mars

Iowa's 1868 tree law gave settlers a five-year tax exemption of $50 an acre for fruit trees set no more than 30 ft apart, and Sioux County's Dutch homesteaders planted one to five acres of trees each, with groves north and west of their houses against winter wind and blizzards. Statewide, the Armistice Day freeze of November 11, 1940 left Iowa's 1941 apple crop at about 15 percent of normal. Le Mars's Hershberger orchard dates to the 1930s; Norm Koch bought it and moved it south of town after the 1980s flood, and as Adventurous Souls Apple Orchard it grows 200 semi-dwarf trees in 20 varieties, Honeycrisp and Haralson among them. Just north of the map, Calico Skies Vineyard at Inwood grows mostly Frontenac, Marquette, Brianna, La Crescent and Frontenac Gris, and Ocheda Orchard in Worthington, Minnesota bred the apple sold as SugarBee.

Questions people ask

What growing zone is Le Mars, Iowa?

On our map Le Mars plans for −31°F, MFTC zone 3b, with a typical winter low of −18°F. Orange City and Sioux Center (both −28°F) are zone 4a, and the Rock and Big Sioux bottoms run −33°F to −35°F. USDA's zones are built on the average winter's coldest night, so they read warmer; ours are built on the bad night you plan for.

When is the last frost in Sioux Center and Le Mars?

NOAA station records for 1991 to 2020 put the median last 32°F at April 28 in Le Mars and May 1 at Sioux Center 2 SE, and 1 year in 10 it comes as late as May 14 and May 15. Sheldon runs latest: May 4, and May 20 in a bad year.

What fruit trees grow in northwest Iowa?

Haralson, Honeycrisp, Frostbite and Zestar!® apples, Ure and Luscious pears, Toka and Superior plums, and Evan's Bali and Meteor tart cherries fit the valley floors at −31°F to −33°F. Apricots, Lapins sweet cherry and Siberian C peach belong on the warm slopes and in town at Orange City and Sioux Center.

Can you grow Honeycrisp in northwest Iowa?

Yes. Honeycrisp has come through −45°F, well past anything on this map, and Altena Apples near Orange City and Adventurous Souls south of Le Mars both grow it.

What grapes grow in northwest Iowa?

Calico Skies Vineyard at Inwood grows mostly Frontenac, Marquette, Brianna, La Crescent and Frontenac Gris. We sell Frontenac and Marquette (−35°F) and Brianna and La Crescent (−40°F); on the cold bottoms, Valiant (−50°F) is safer.

Where are the frost pockets around Le Mars and Sioux Center?

The river bottoms, colder toward the north: Fairview on the Big Sioux plans for −35°F and the Rock River floor at Rock Valley −33°F to −34°F. At bloom, Brunsville, Carnes, Struble and Alton read 2°F to 4°F colder than Le Mars, while the slopes around Lebanon, Ireton and Crathorne read 4°F to 5°F warmer.

Warmer spots, colder spots

Here's the number to plan for at named places on the map, warmest first. Each one is the 1-in-30-year low for that spot: the cold hardiness calculator's number from the same weather stations, sharpened by our microclimate model for the ground right there. Zone is our MFTC zone, set by that one bad night, not by an average.

The weather stations behind it

These are the long-record stations in and around this map, with each one's own numbers since the winter of 1995-96. The last column is this map's 30-year number right at the station, which won't match the station exactly: it's a blend of the stations around it, the way the calculator works everywhere.

Source: NOAA records through ACIS, winters 1995-96 through 2025-26. What the "carried forward," "gaps filled" and AWOS rows mean is explained in how our microclimate maps work.