Fruit Trees for Rockford, Loves Park and the Rock River, Illinois

On January 31, 2019, the Greater Rockford Airport hit −31°F, Rockford's all-time record low, and on the satellite picture that morning NWS Chicago could see the city's own heat as a warm spot in the cold. That's the story of growing fruit trees for Rockford, Loves Park and the Rock River: arctic air that fills the whole valley, and small differences in where you stand.

The map covers Winnebago County and the northern parts of Ogle and Boone counties in northern Illinois, from South Beloit and Rockton at the Wisconsin line through Roscoe, Machesney Park, Loves Park and Rockford to Byron and Stillman Valley. 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

The big number is the 30-year planning low our cold hardiness calculator uses (NOAA station records since the 1995-96 winter), with a small nudge for the ground around you. It's a safe number to plan around, not the record and not a promise of how often it comes. The MFTC zone is that number in half zones. The typical winter is an average year's coldest night, the kind of average USDA's map uses. The spring layer shows how much warmer or colder a spot runs than downtown Rockford on a still, clear night at bloom.

Downtown plans for −27°F, MFTC zone 4a, typical winter −13°F, the middle of the map; nine tenths of the growing ground falls between −30°F and −25°F. The warm end is Bergen and Hunter, near 960 feet on the Boone County upland, at −25°F. The cold end is the Rock bottom from south Rockford to Byron, where Blackhawk Island Subdivision and Von Glen Acres sit a hair past −30°F, which tips them into MFTC 3b. The spring layer swings wider, from 3°F colder than downtown at Riverdale, on the Rock at Roscoe, to 12°F warmer at Woodcrest, on an 11 percent slope on the southwest side.

Why the map looks the way it does

Everything drains to the Rock. The river comes out of Wisconsin, takes in the Pecatonica (just after it picks up the Sugar) at Rockton, runs through the Fordham dam's pool at about 703 feet from Machesney Park to downtown, drops to about 690 feet below the dam, takes the Kishwaukee near the airport, and leaves the map below Byron at about 672 feet, the lowest ground on it. Spring, Keith and Kent creeks carry the city's upland cold down to it, and off the east and southeast uplands (840 to 900 feet) the paths are short and steep. On a clear, calm night the ground radiates its heat to the sky, chilled air slides down the draws, and most of the pool is made right on the floor.

The winter numbers don't spread far, and NOAA station records show why: no long-record station pair here differs by 3°F or more in the median year's coldest reading. Deep arctic air fills the whole Rock River Valley, benches and all. Position still shows. On the 2019 record morning the airport, on a low terrace between the Rock and Kishwaukee bottoms at 725 feet, read −31°F while DeKalb, at 878 feet, read −26°F. And around Byron, where the river runs at 678 to 685 feet below bluffs 130 to 160 feet high, the floor plans for −30°F and the benches −27°F.

The station that stands apart is just north of the map in the Sugar River valley. Brodhead's wastewater plant read −36°F on January 30, 1951, when the old Rockford station read −22°F, and −34°F on February 3, 1996, when the Rockford airport read −24°F. The Sugar meets the Pecatonica near Shirland, and together they spread into a flat at 716 to 728 feet reaching 5 miles or more west of the Rock, with oxbows, wetlands, bottomland forest and mapped peat and muck. A wide, flat basin can pool harder than a deep valley that drains, and low, grassy, organic ground gives back little heat on a clear night.

Height above the nearest low ground beats elevation. Argyle, at 884 feet but only 10 feet above its floor, plans for −28°F; Colonial Gardens, at 773 feet and 50 feet above its floor, −26°F. Around most towns the benches 100 to 700 feet up plan 2°F to 3°F warmer than the floor within 3 miles, and the spring layer, which takes the terrain at full strength, swings more. A Hungarian study of 69 clear, calm nights found a valley floor averaged 6.7°F colder than a slope 230 feet higher. Towns hold heat (the map gives built-up ground up to 2.5°F), but water does little: nobody has documented when the Rock freezes here, a river floor is still a floor, and Lake Michigan is 75 to 90 miles east.

The soils follow the ground: sandy, gravelly outwash on the terraces along the Rock and lower Pecatonica (it drains fast and dries out), loess on the uplands, and peat, muck and floodable lake clay in the bottoms, which run cold and wet. Snow is the wild card. Air over snow runs colder, but 4 to 10 inches of it insulates the soil, and dormant apple roots are seriously hurt near 10°F while the wood above takes about −40°F.

Downtown Rockford and the river bottoms

The river at downtown sits about 706 feet; the west side is a low terrace (715 to 735 feet) for about a mile and a half, and the east side rises to about 800 feet within 1.3 miles. Downtown is river-bottom ground: −27°F, MFTC 4a, typical winter −13°F, with the floor within 3 miles at −27°F and the benches and bluffs −25°F.

The oldest neighborhoods hug the river at 720 to 760 feet: Churchill's Grove (about 723 feet), Coronado Haskell, Edgewater, North End Square, Beverly Park and Riverview. That's floor ground, with downtown's heat helping the blocks closest in. Haight Village (752 feet) and Brown's Hills/Knightsville (791 feet) on the east side sit up the valley side, with somewhere for cold air to go, and Keith Creek, which flooded the near east side in 2006 and 2007, is a cold-air path as much as a water path.

South of downtown the bottoms widen toward the Kishwaukee's mouth, and this is the coldest part of the city. Factory Addition (728 feet), Franklin Gardens (716 feet), Indian Village and Kinseys Little Farms plan for −29°F. Blackhawk Island Subdivision, at 695 feet on the river bottom, plans a hair past −30°F (MFTC 3b), typical winter −16°F. The airport station's own 30-year number is −29°F, a degree colder than the map gives that spot, and its median last spring frost (April 26) comes later than Beloit's (April 22) or DeKalb's (April 18), both higher, which fits cold air settling on that low terrace.

Downtown's −27°F leaves room for Liberty and Enterprise apples (−30°F), two of Illinois Extension's disease-resistant picks, and for Lapins and Gold, the hardiest sweet cherries we've found (−35°F). On the south-side bottoms, lean on Honeycrisp and Haralson (−45°F) and Ure pear (−40°F), on ground that doesn't flood.

Southeast Rockford: Atwood, Kishwaukee Glen and the upland between the rivers

The southeast side is a ridge of about 840 to 850 feet between the Rock bottom and airport terrace (690 to 735 feet) and the Kishwaukee valley (705 to 720 feet). Cold air has short, steep paths off it both ways, which makes it some of the best bloom-night ground on the map. Kishwaukee Glen (834 feet, 100 feet above its floor) and Silver Hills read 8°F warmer than downtown at bloom, Green View Heights and Lonesome Acres 7°F, and Canyon Ridge, Greenridge Estates, Atwood Park Estates and Shepardson Subdivision 6°F.

In winter it runs about even with downtown: Kishwaukee Glen, Shepardson Subdivision and Burr Oak Acres plan for −27°F, Atwood Estates and Canyon Ridge −28°F. Deep winter nights fill wider than bloom nights, and the 30-year number takes the fine terrain at only a quarter strength. Hollows still catch cold: Cheyenne Heights and Cleveland Subdivision plan for −28°F and read 1°F colder than downtown at bloom. Farther east, the city's highest neighborhoods (Country Club Estates, Spring Lake, Gregory Heights and Tower Hill Estates, 859 to 900 feet) stand 150 to 200 feet above the river. High ground helps only where the cold can drain: Samuelson Corners, on level ground at 785 feet on the northeast side, reads 2°F colder at bloom.

This is apricot and peach ground. Westcot (−45°F) and Sungold (−40°F) apricots clear the winter number easily. Contender (−30°F), the only commercial peach we know of that has taken −32°F, clears it by 2°F to 3°F, and Siberian C (−35°F), the hardiest peach we think is out there, by more. Put them on slopes reading 5°F or more warmer at bloom.

The west side and Winnebago

West of the river, Rockford climbs from the terrace to 815 to 845 feet 3 to 5 miles out, drained by Kent Creek; Serenity, SWIFTT, Cottonwood and Kelly Meadow sit at 811 to 819 feet. Westmoreland, at 808 feet, plans for −27°F and reads 4°F warmer than downtown at bloom. Southwest of the city the slopes steepen. Woodcrest, 100 feet above its floor, reads 12°F warmer at bloom, the warmest spring reading of any named place on the map, and Grant View Heights and Motor Heights 6°F warmer. Yet Motor Heights plans for −29°F: this corner runs colder in winter, like the Rock bottoms toward Byron, so pick the tree for the winter number and the spot for the spring one.

Winnebago village sits on the western upland at 869 feet, 50 feet above its floor: −27°F, MFTC 4a, typical winter −12°F, with the floor around it at −28°F. Alworth, Wempletown and Owen Center plan for −26°F, and Wempletown, 100 feet above its floor, reads 6°F warmer at bloom. Edwards Apple Orchard West is on Cemetery Road in Winnebago. The Winnebago soil series, named for this county, and its neighbors Argyle and Pecatonica are loess soils on upland prairie slopes, the deep, well-drained orchard soil here. Northern Spy apple, Stanley plum and Montmorency tart cherry (all −30°F) have room up here.

Loves Park, Machesney Park and Harlem

North of downtown the Fordham pool has a flat of 704 to 750 feet on both banks before the ground steps up to 830 to 900 feet, with Rock Cut State Park on the east side. Loves Park's riverside point, at 719 feet, plans for −28°F, MFTC 4a, typical winter −14°F, even with downtown at bloom; its floor plans for −27°F and benches −26°F. Machesney Park, on the flat at 740 feet, plans for −27°F and reads 1°F warmer at bloom. Harlem, the township and school district name for this side, sits 30 feet above the floor at −26°F, 2°F warmer at bloom, and Ruby, on a toe slope, reads 5°F warmer. Rock Cut's Pierce Lake, about 11 feet deep on average, is too shallow to warm anything once it freezes.

On these flats, Zestar!® and Cortland apples (−40°F) and Superior and Italian plums (−35°F) clear the number by 7°F or more. Toka pollenizes Superior well; our pollination maps show what pairs with what.

Roscoe, Rockton, Shirland and the Stateline

Above the pool the Rock runs at 705 to 712 feet. Roscoe, named in 1837 for a rocky ford, plans for −27°F, typical winter −14°F, even with downtown at bloom. Riverdale, at river level at 716 feet, plans for −29°F and reads 3°F colder than downtown at bloom, the coldest spring reading of any named place on the map, while Stagecoach Hills, east of Roscoe and 70 feet above its floor, plans for −26°F and reads 5°F warmer. Rockton, where the Pecatonica comes in, plans for −28°F, with the floor around it at −27°F and the benches −25°F. South Beloit, across the state line from Beloit, plans for −28°F, has no bench ground within 3 miles, and sits on thick sand that drains fast and dries out, so mulch young trees. The Janesville and Beloit map carries on up the Rock.

West of Rockton lie the Pecatonica and Sugar flats, where the Pecatonica has flooded seven times since May 2017. Shirland plans for −28°F and reads 1°F colder than downtown at bloom; Harrison, on the river bottom, plans for −27°F and reads 2°F colder. Around both the floor plans for −28°F and the benches −25°F. Durand, in the northwest corner, plans for −29°F and is the only town on the map with more bench ground than floor within 3 miles; those benches plan for −26°F. In the river towns, Empire and Paula Red apples (−35°F) have room. On the flats, with Brodhead up the Sugar in mind, go hardier: Wolf River apple (−45°F), Summercrisp pear and Alderman plum (−40°F).

Cherry Valley and the Boone County upland

Cherry Valley (named in a hat drawing, not for cherry trees) sits in a slight depression just north of where the Kishwaukee's north and south branches meet, on a valley floor of 714 to 720 feet with ground rising to 825 to 890 feet within about 3 miles north. The village point, on a toe slope at 768 feet, plans for −28°F, typical winter −13°F, 1°F warmer than downtown at bloom, with the floor around it at −28°F and the benches −26°F. Valley View, down at 728 feet, plans for −29°F. Valley Orchard on East State Street grows about 5,000 apple trees on 35 acres, plus raspberries, blueberries and currants.

North and east the land climbs into Boone County. Caledonia (933 feet) plans for −26°F, and Bergen and Hunter, by the state line near the highest ground on the map (about 1,009 feet), −25°F. Even up there the low spots collect cold: Timberlane, on a toe slope at 839 feet, reads 2°F colder than downtown at bloom. Harlayne apricot and Rainier cherry (−30°F) clear the upland's number by 4°F to 5°F. East toward Chicago, the western suburbs and Fox Valley map takes over.

Byron, Stillman Valley and the south

Below the Kishwaukee mouth is the map's cold corner. Byron sits on flat land by the river, with bluffs to about 810 feet within a mile and a half east. The village point, 40 feet above its floor, plans for −29°F, MFTC 4a, typical winter −14°F, and reads 3°F warmer than downtown at bloom; the floor around it plans for −30°F and the benches −27°F. Von Glen Acres (691 feet) and Loose Pulley Junction plan a hair past −30°F (MFTC 3b). Stillman Valley, on Stillman Creek at 709 feet, plans for −30°F, typical winter −15°F. Davis Junction, 50 feet above its floor, plans for −28°F, though the floor around it plans for −30°F, and Monroe Center, on a toe slope 80 feet up, is the warm spot of the south at −26°F and 4°F warmer at bloom.

At −30°F I'd plant for the record: Wealthy (−50°F) and Frostbite (−45°F) apples, Kerr (−50°F) and Trailman (−60°F) applecrabs (if you only plant one tree, make it one of these), and Evan's Bali tart cherry (−45°F).

Spring frost and bloom along the Rock

The spring layer follows the same drainage as winter, at full strength: warmest on slopes with low ground below (Woodcrest 12°F warmer than downtown), coldest on flats with nowhere to send the cold (Riverdale 3°F colder). Open blossoms of apple, pear, cherry, peach, apricot and plum start dying near 28°F, and NC State's fruit people say 3°F to 4°F can separate no crop from a full one.

NOAA's 1991 to 2020 station records put the airport's median last 32°F at April 26 and last 28°F at April 13; one spring in ten the last 32°F comes May 16 or later. Beloit's median is April 22, DeKalb's April 18, Brodhead's April 30 and Clinton's, just over the Wisconsin line, May 9. The airport gets a median 166 frost-free days, well past the 135 days the University of Vermont uses to mark short-season fruit country.

Bloom frost is what costs crops here. In 2007 a record-warm late March was followed by lows of 18°F to 20°F across northern Illinois on April 4 to 9; northern Illinois apples weren't far enough along to be hurt, though strong winds mixed the air so even sheltered sites took damage. In 2012, after a very warm March, some northern Illinois growers reported near-complete losses of most varieties, Honeycrisp included. In 2026 spring came a week or two early: Prairie Sky Orchard in Union, east of the map, took five frosts in bloom with no frost fans and lost about 99 percent of its blossoms, while Jonamac Orchard in Malta ran its fans and got mostly frost rings. A study co-authored by state climatologist Trent Ford projects apple full bloom one to two weeks earlier by mid-century, which pulls blossoms into weeks that still freeze.

The fix is mostly site. Put apricots, peaches and sweet cherries on the slopes that read warmest, and keep apples, pears, honeyberries and bush fruit for flatter ground: only about 15 percent of apple blossoms need to set for a crop, and fully open haskap (honeyberry) flowers take 19°F. Bob Purvis's rules fit: an east-facing slope warms quickly on a frosty morning, and brush or a tree line at the bottom of a slope dams cold air into the trees above it. Through bloom, mow short, don't till, and water a day or two before a frost; frost cloth of 0.5, 0.9 and 1.5 ounces per square yard gains about 4°F, 6°F and 8°F. Frost fans help only on still, clear nights, not in a windy freeze like 2007's.

What the weather records say

The coldest NOAA station readings on file: −36°F at Brodhead (January 30, 1951); −31°F at the Rockford airport (January 31, 2019, in 75 years on file), matched that morning at Rochelle's airport; −29°F at Beloit the same morning; −28°F at Clinton (2009); −27°F at DeKalb (1985); −26°F at the old Winnebago and Kishwaukee stations (1905); and −25°F at the old Rockford station (1924 and 1933). Wikipedia's county page still gives an out-of-date −27°F record from 1982.

The airport's own 30-year number is −29°F, and in 2019 it went 2°F past it, so I like a few degrees of room. USDA's 2023 map puts every ZIP we checked here in zone 5b (−15°F to −10°F), from 61101, 61107 and 61109 in Rockford to 61115 in Machesney Park and 61010 in Byron. Our MFTC zone for downtown is 4a, more than a full zone colder, because NOAA station records show the worst night in about 30 winters runs a median 13°F below a station's average winter low. Timing matters too: the airport's median first 32°F comes October 13, and a freeze before trees harden off kills at temperatures a January tree shrugs off, so we taper water from mid-August.

What you can grow here

Uplands and slopes that plan for −26°F or warmer

Bergen, Hunter, Caledonia, Monroe Center, Alworth, Wempletown, Harlem and Stagecoach Hills.

• Apples: Liberty, Enterprise, Northern Spy and Cox Orange Pippin (−30°F).
• Pears, plums and cherries: Harrow Sweet pear, Stanley plum, Rainier, Stella and Montmorency cherries (all −30°F).
• Apricots and peaches: Harlayne apricot, Contender and Veteran peaches (−30°F). Worth a try: Blushingstar peach (−25°F), right at the number at Bergen and Hunter and 1°F short elsewhere; it came through −25°F at our place on January 13, 2024 without damage.

Rockford, the river towns and most of the map: −27°F to −29°F

Downtown, Loves Park, Machesney Park, Roscoe, Rockton, South Beloit, Cherry Valley, Winnebago, Durand, Shirland, Harrison and the southeast subdivisions.

• Apples: Empire, Paula Red and Macoun (−35°F); Zestar!®, Cortland and Golden Russet (−40°F); Honeycrisp, Haralson and Snowsweet® (−45°F), all grown at Valley Orchard.
• Pears and plums: Bartlett (−35°F) and Ure (−40°F) pears; Superior and Italian (−35°F) with Toka (−45°F).
• Cherries: Lapins and Gold (−35°F), Meteor tart (−40°F).
• Peaches and apricots, on slopes: Siberian C (−35°F), Hardy Iowa (−35°F) and Sungold (−40°F). Contender and Veteran (−30°F) fit the −27°F and −28°F ground.
• Berries and vines: honeyberries and Montana Black Currant (−50°F), Pixwell gooseberry and Boyne raspberry (−40°F), Frontenac grape (−35°F).

The south-side Rock bottoms, Byron and Stillman Valley: −30°F and a little colder

With −31°F on record at the airport, favor −40°F and colder.

• Apples: Wealthy (−50°F), Haralson, Frostbite and Wolf River (−45°F); Kerr and Centennial (−50°F) and Trailman (−60°F) applecrabs. Ed Schultz saw zero winter injury on Centennial after a winter that hit −47°F.
• Pears and plums: Ure, Summercrisp and Luscious (−40°F); Toka (−45°F) and Alderman (−40°F).
• Cherries and apricots: Evan's Bali (−45°F) and Meteor (−40°F) tart cherries; Romeo dwarf cherry (−50°F); Westcot apricot (−45°F) on the bluffs.
• Berries: honeyberries, Montana Black Currant and Aronia (−50°F), Red Lake currant (−40°F). Our Red Lake and Montana Black Currant fruited in 2026 after their flower buds saw about 22°F.

Illinois Extension calls apple the main backyard fruit tree in northern Illinois because it's so winter hardy. Apples need a second variety blooming at the same time, and a flowering crabapple like Dolgo (−55°F) makes a good pollenizer. Extension's local problems are deer (use tree guards), voles and mice (keep mulch off the trunk), and apple scab, cedar-apple rust and powdery mildew. Stay out of the flood bottoms. On sandy outwash, mulch and keep the soil moist into winter, since dry soil and a snowless winter are what kill roots. On muck and lake clay, test drainage first (dig 2 feet, fill, let drain, refill; under 10 hours is well drained). Drip is the only irrigation we advise.

Fruit history here

Rockford has been the Forest City since the New York Tribune called it that in 1853, and Klehm Arboretum began in 1910 as Rockford Nursery. Edwards Orchard, in Poplar Grove just east of the map, grew out of the family dairy on Centerville Road; Bob and Betty Edwards planted the first apple trees in spring 1964 and sold the first bushels from a hayrack.

Questions people ask

What growing zone is Rockford, IL?

Downtown Rockford plans for −27°F, MFTC zone 4a, with a typical winter of −13°F. USDA's 2023 map puts every Rockford-area ZIP we checked in zone 5b (−15°F to −10°F). USDA's zone is based on an average winter, ours on the bad night we plan for, and the airport hit −31°F in 2019.

When is the last frost in Rockford?

NOAA station records for 1991 to 2020 put the airport's median last 32°F on April 26 and last 28°F on April 13. One spring in ten the last 32°F comes May 16 or later. River bottoms and the Pecatonica flats run later, the slopes earlier.

Can you grow peaches in Rockford?

Yes, with the right variety and spot. Contender and Veteran (−30°F) clear the planning low on most of the ground here, and Siberian C (−35°F) clears all of it. Peaches bloom early, so plant them on slopes that read warm at bloom, like Rockford's southeast upland.

Where does cold air settle around Rockford?

On the Rock bottoms south of downtown (−29°F to −30°F), along the Rock to Byron and Stillman Valley (−30°F), and on the flat river edges at Roscoe, Shirland and Harrison, which read 1°F to 3°F colder than downtown on a still bloom night. The southeast upland drains the cold away.

What are the best apple trees for northern Illinois?

Most of the Rockford area plans for −27°F to −29°F, which suits Honeycrisp, Haralson, Snowsweet®, Zestar!® and Cortland, all grown at Valley Orchard in Cherry Valley. For less spraying, Illinois Extension names Liberty and Enterprise (−30°F), which fit everywhere but the coldest bottoms. Add a crabapple like Dolgo as a pollenizer.

Why does my yard frost earlier than town?

Town heat and low spots. Buildings and pavement hold heat on calm, clear nights, and cold air settles in low ground, so a rural yard on a river bottom can frost when downtown doesn't. Riverdale at Roscoe reads 3°F colder than downtown on a still bloom night, while Kishwaukee Glen reads 8°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.