Fruit Trees for Twin Falls, Jerome, Buhl and the Magic Valley, Idaho

On April 17 and 18, 2026, Kelley's Canyon Orchard, down on the floor of the Snake River Canyon, sat at 26°F for more than three hours. The cherries that had set turned black and the peaches started dropping. Two years earlier, the April 16 and 17, 2024 freeze took nearly everything. When it comes to fruit trees for Twin Falls, Jerome, Buhl and the Magic Valley, winter rules out less than you'd think. Bloom nights decide most crops, and they don't hit every farm the same.

This map covers the western core of the Magic Valley in south-central Idaho: Twin Falls and the south side of the canyon from Murtaugh out to Buhl, Castleford and Hollister; Jerome, Eden and Hazelton on the North Side, with Wendell to the west; and the Hagerman Valley at the low west end. It stops at Milner Dam, so for a Burley or Rupert address use our cold hardiness calculator. 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 number on the map is the 30-year planning low, the number to plan for at that spot. Our cold hardiness calculator uses the same number; it leans to the safe side and it isn't the record. The MFTC zone is that number in half zones. "Typical winter" is an average year's coldest night, the kind of number USDA zones are built on, which is why Utah State's calculated zones put Twin Falls in 6b and we put it in 5a. The spring layer shows how many degrees warmer or colder each spot runs than Twin Falls on a still, clear night at bloom.

The middle of the map's growing ground plans for −16°F (MFTC 5a), and half of it falls between −17°F and −15°F. The warm end is Buhl at −13°F (MFTC 5b) and the lava buttes, with the warmest twentieth of the ground at −13°F or better. The cold end is Eden, Murtaugh, Milner and the flats east of Hazelton at −18°F to −19°F, with the coldest twentieth at −20°F or worse. Twin Falls, the reference point, plans for −15°F (MFTC 5a), typical winter about 0°F. Several towns sit within a fraction of a degree of −15°F, the 5a and 5b line, so −15°F can carry either zone. The bigger spread is in spring: nearly 10°F at bloom between Hagerman and Deep Creek, and more where the buttes rise off the plain.

Why the map looks the way it does

This part of the Snake River Plain is a broad lava plain tilted gently west, with the Snake River Canyon cut up to 500 feet into it. The river falls from roughly 4,200 feet at Milner Dam to about 2,900 feet at Hagerman. Lava buttes stand a few hundred feet above the plain, and most towns sit on slopes of 1 to 3 percent. Most of a cold pool is made right where it sits, as the ground radiates heat to a clear sky, and on ground this flat the cold has no quick way out; a wide, shallow stretch like this can pool harder than a deep valley that drains. On a bigger scale, the National Weather Service in Boise found inversion-trapped cold air and fog tend to drain from the Magic Valley west toward the Treasure Valley.

The east end is the cold end. In NOAA station records, Hazelton runs a median 3°F to 4°F colder than the old Twin Falls stations on the year's coldest night, and the old Milner Dam station, at the canyon head, ran 5°F colder than Jerome. On January 21, 1937, Hazelton read −32°F while the station 3 miles southeast of Twin Falls read −12°F. We haven't found a published local explanation, but the terrain fits: around Eden and Hazelton it's open flats at 3,950 to 4,100 feet between Skeleton, Hazelton and Cinder buttes, with a lot of floor and little relief. Within 3 miles of Hazelton the floor plans for −19°F and the benches −16°F. Within 3 miles of Buhl, Filer and Jerome the map finds no valley floor at all.

The west end of the Twin Falls tract is the warm end. Buhl sits on a bench 200 feet above the nearby low ground, so its cold drains off instead of settling. Since 1995 the Buhl station's average winter low is about 2°F, the mildest on the map; on that 1937 morning it read −18°F. The lowest ground isn't the warmest, though. The Hagerman Valley floor, around 2,900 feet, plans for −16°F, and the Hagerman station's −18°F in the 2016-17 winter is the coldest reading on the map since 1995. A river floor is still a floor.

Height above the floor is what the spring layer reads. Skeleton Butte, 450 feet above the low ground near Eden, reads 11°F warmer than Twin Falls on a still bloom night, and Hub Butte south of Twin Falls 9°F warmer. A Hungarian study of 69 clear, calm nights found a valley floor averaged 6.7°F colder than a slope 230 feet higher. In winter the buttes gain less (Hub Butte plans for −12°F), because the winter number leans on the station records and takes fine terrain at a quarter strength, while the spring layer is terrain at full strength.

In midwinter the plain sits under inversions. The Trail Gulch station, at 6,000 feet on the south edge of the map, has an average yearly low of 4°F, against −11°F to 0°F at the valley stations, and KMVT described valley fog hanging on under a warm layer in the 2021-22 winter. The sorting breaks down when arctic air comes in deep: on December 22, 1990, every station inside the map read between −21°F and −27°F, and Hazelton (−23°F) was milder than Buhl (−26°F). Wind mixes it too; orchard inversions usually hold only while the wind stays under 3 to 5 mph. Town heat doesn't stand out on the map here: around downtown Twin Falls the warmest and coldest tenths of growing ground plan under 2°F apart.

Twin Falls, Kimberly and Hansen

Twin Falls sits at about 3,740 feet on the plain along the south rim, roughly 485 feet above the crest of Shoshone Falls. It's nearly dead flat, 70 feet above the lowest ground nearby, so there's no deep pool and no real bench in town. It plans for −15°F (MFTC 5a), typical winter about 0°F. Small height differences still show: the old station 2 miles north-northeast of town sat about 80 feet below the one 3 miles southeast and ran colder in most big outbreaks.

The edges of town differ more at bloom than in winter. Knull, 5 miles west-southwest on a bench 170 feet up, plans for −15°F (MFTC 5b) and reads slightly warmer than town in spring, the best spring ground near the city. McMillan, toward Kimberly, and Godwin, just past Knull to the southwest, plan for −15°F but read 3°F colder at bloom, and Berger, farther south, plans for −16°F and reads 4°F colder.

Kimberly, one of the towns laid out from I. B. Perrine's original survey lots, sits at about 3,914 feet, 80 feet above the low ground. It plans for −16°F (MFTC 5a) and reads 1°F colder than Twin Falls at bloom. Hansen, 3 miles east on a bench 100 feet up, plans for −16°F and reads within 1°F of Twin Falls. Tipperary Corner, north of Hansen on a 6 percent slope where cold drains past, reads 1°F warmer than Twin Falls in spring, and Stricker Butte, south of Kimberly, plans for −13°F and reads 6°F warmer. The cold ground here is the Rock Creek bottom south of Hansen: −17°F, and 4°F colder at bloom. Put apricots, peaches and sweet cherries on spots like Knull and Tipperary Corner, and give McMillan, Godwin and Rock Creek apples, pears and bush fruit.

Buhl, Filer and Castleford

Buhl is the warmest town on the map: −13°F (MFTC 5b), typical winter about 2°F, and 2°F warmer than Twin Falls at bloom. The Buhl station's median last 28°F is April 14, the earliest on the map, and its first fall 28°F October 29, the latest, with 156 frost-free days. Buhl calls itself the Trout Capital of the World, and its historical marker mentions orchards selling fresh fruit. Cedar, 3 miles east, and Clover and Fairview to the south plan for −14°F (MFTC 5b) but read about 2°F colder than Twin Falls at bloom.

Deep Creek, 4 miles west of Buhl at 3,602 feet, is the warning. It plans for −15°F, but it reads 7°F colder than Twin Falls on a bloom night, the worst spring reading of any named place on the map, because it sits on lower ground where cold settles. Castleford, 8 miles southwest of Buhl, sits on a floor 40 feet above its low ground, plans for −15°F (MFTC 5b) and reads 3°F colder at bloom. Its station's median last 32°F is May 12, nine days after Buhl's, and it was the coldest station on the map on December 11, 1972 (−25°F) and January 18, 1984 (−23°F).

Filer, 7 miles west of Twin Falls and named for Walter G. Filer, who supervised building Milner Dam, is on a bench 110 feet up. It plans for −15°F, about 0.5°F warmer than Twin Falls, which tips it into MFTC 5b, and reads 1°F colder at bloom. Buhl's bench is the place for Contender peach, Lapins cherry and Harlayne apricot; keep them off Deep Creek and Castleford's floor.

The canyon, Thousand Springs and the Hagerman Valley

Below Milner Dam, aquifer springs pouring out of the north canyon wall refill the Snake. Kelley's Canyon Orchard started on the canyon floor in 1908 with Elberta peaches from Stark Bros, and the fourth generation now grows cherries, apricots, nine peach varieties, plums, nectarines, apples and pears. The family says the canyon runs about 3°F warmer than the land around it, from the rock holding heat and the river steadying things. That helps early buds, but it didn't save the 2024 crop or the 2026 cherries.

Hagerman, at about 2,970 feet, is the lowest town on the map, some 770 feet below Twin Falls, in a valley known for Thousand Springs and its trout farms. It sits on a toe slope 90 feet above the river floor and plans for −15°F (MFTC 5b, just over the line), typical winter about 2°F, and reads 2°F warmer than Twin Falls at bloom. The floor around it plans for −16°F and the benches −14°F, so climbing out of the bottom is worth about 2°F. The Hagerman station shares Buhl's May 3 median last frost, but its first fall 32°F comes October 1. Gertschen Vineyard in Hagerman supplies the Syrah for Holesinsky Winery's rosé in Buhl; Marquette has come through −35°F, plenty for the slopes above the floor.

Jerome, Wendell and the North Side

Jerome, across the canyon from Twin Falls at about 3,750 feet, got its water from the North Side Canal, finished with Milner Dam in 1905. Town is on a bench 120 feet above the low ground and plans for −15°F, right on the line between MFTC 5a and 5b, typical winter about 1°F. At bloom it reads 2°F warmer than Twin Falls, among the best of any town. Since the 1995-96 winter the Jerome station hasn't read colder than −13°F, yet the map plans for −15°F in town and −16°F at the station; that's the number leaning safe.

Village West Mobile Home Park, under a mile northwest of downtown on slightly lower ground, plans for −16°F (MFTC 5a) and reads 3°F worse at bloom than central Jerome. Barrymore and Falls City, between Jerome and the canyon, plan for −15°F (MFTC 5b). The flats farther east are worse in spring: Sugar Loaf plans for −16°F and reads 4°F colder, and Perrine plans for −17°F and reads 6°F colder.

Wendell, at 3,437 feet, sits on a floor 70 feet above the lowest ground with almost no bench within 3 miles. It plans for −15°F (MFTC 5a) and reads 2°F colder than Twin Falls at bloom, and Appleton, east of it, reads 4°F colder. Out on the open lava plain at the northeast corner, Owinza, only 10 feet above its low ground, plans for −24°F (MFTC 4b), the coldest named place on the map. Jerome's lots can carry sweet cherries and late-blooming apricots like Sungold; on Wendell's floor, Sugar Loaf and Perrine, plant later-blooming apples, pears and plums.

Eden, Hazelton, Murtaugh and Milner

Eden, at about 3,960 feet, is only 20 feet above its low ground. It plans for −18°F (MFTC 5a), typical winter about −3°F, and reads 4°F colder than Twin Falls at bloom. Around Eden the floor plans for −18°F and the benches −15°F, the biggest step of any town here, so a little height pays more here than around any other town.

Hazelton, 4 miles east at 4,069 feet, plans for −17°F (MFTC 5a) and reads 1°F colder than Twin Falls at bloom. Its station has 85 years on file, a record of −32°F (January 21, 1937) and an average winter low since 1995 of about −3°F, yet a 152-day frost-free season. The flats east of town are the coldest farm ground on this end: Greenwood and McHenry plan for −19°F and read 7°F and 5°F colder at bloom. Hazelton Butte, 3 miles southeast, plans for −15°F and reads 7°F warmer.

Murtaugh, another Perrine survey town at about 4,085 feet, sits 30 feet above its low ground and plans for −19°F (MFTC 5a), reading 2°F colder at bloom. Milner, on the river bottom near Milner Dam, plans for −19°F and reads 3°F colder. Don't count on Milner Lake to warm its shore. The old Milner Dam station had the coldest average yearly low of any station inside the map, −11°F. Out here, plant from the coldest band below, and put any apricot on a butte flank rather than the flat.

Hollister and the south hills

Hollister, 15 miles south-southwest of Twin Falls at about 4,520 feet, plans for −17°F (MFTC 5a) and sits near the cold end of its own 3-mile circle, where the benches plan for −15°F. The Hollister station runs a median 4°F colder than Buhl and read −27°F on December 22, 1990, yet Hollister reads 1°F warmer than Twin Falls at bloom. Roseworth, on a bench at about 4,630 feet, plans for −14°F (MFTC 5b), and Berger Butte and Hub Butte plan for −12°F. The University of Idaho's short-season bulletin, written for ground above 4,500 feet, lists Haralson apple, Ure pear, Toka plum and Meteor pie cherry; each has come through −40°F or colder.

Spring frost and bloom in the Magic Valley

The best spring ground on the map is the butte slopes, 5°F to 11°F warmer than Twin Falls on a still bloom night, and among towns Hagerman, Jerome and Buhl, each about 2°F warmer. The worst is the low ground: Deep Creek and Greenwood 7°F colder, Perrine 6°F, and Sugar Loaf, Berger, Rock Creek and Eden about 4°F colder. NC State's fruit people say 3°F to 4°F can separate no crop from a full one.

NOAA station records for 1991 to 2020 put the median last 32°F at May 3 at Buhl and Hagerman, May 6 at Jerome, May 9 at Hazelton and the Twin Falls airport, and May 20 at Rock Lake on the map's edge; one year in ten it comes after June 3 east of Twin Falls. The last 28°F, where open blossoms start dying, comes April 14 at Buhl, April 19 at the Twin Falls airport and April 30 east of town. The 2024 and 2026 freezes landed right in that window.

Kelley's 2026 freeze sorted the fruit by bloom date. The cherries and apricots, first to open, took the worst of it (the family figured on a 5 percent cherry crop), and the later apples and pears still looked like a crop. Open blossoms of apple, pear, cherry, peach, apricot and plum all start dying at about 28°F. Not every blossom has to make it, though: only about 15 percent of apple blossoms need to set for a crop, sweet cherries can lose half their flowers and still have a full crop, and fully open haskap flowers take 19°F.

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 ground that reads even with Twin Falls or better in spring, and give ground reading 4°F or more colder to apples, pears, haskap and currants. Bob Purvis's rule fits: an east-facing slope warms quickly on a frosty morning, and a north slope holds early bloomers back. A hedge, fence or tree line across a slope can back cold air up into the trees just uphill of it. Through bloom, mow under 2 inches, don't till, and water a day or two before a frost. Kelley's added a big fan after 2024, but a wind machine gains only a third to a half of the inversion, and nothing in a windy freeze. For apricots, the University of Idaho recommends late bloomers like Perfection and Westcot, and warns they may crop only about one year in five.

What the weather records say

Among the coldest readings in NOAA station records here are −36°F at Shoshone, just past the north edge (January 21, 1937), −34°F at Rock Lake (December 22, 1990), −32°F at Hazelton (January 21, 1937), and −30°F at the old station north-northeast of Twin Falls (January 19, 1922) and at Milner Dam (January 21, 1937). Hollister has read −27°F, Buhl and Castleford −26°F, and Jerome and Hagerman −25°F. December 1990 came after a mild fall, ran −21°F to −27°F at every station inside the map and hung on for about two weeks; Snake River Valley vineyards saw −20°F or lower.

Frost-free seasons run from 128 days at Rock Lake to 156 at Buhl, most of the plain at 136 to 153. Twin Falls gets about 10.8 inches of precipitation a year, under an inch a month from June through October. Utah State's calculated zones put the Twin Falls airport, Buhl, Jerome and Hagerman in 6b (an average yearly low about −0.4°F), close to our typical winter; we plan for the bad night instead.

What you can grow in the Magic Valley

Almost everything we sell has come through colder than the −13°F to −20°F planning lows here, so the sorting is mostly bloom. Every variety below has come through at least 10°F past its band's planning low.

Buhl, Filer, Castleford, Hagerman and the warm benches: −15°F or warmer

Apples: Honeycrisp, Cox Orange Pippin and Stayman Winesap. Pears: Bartlett and Seckel. Plum: Italian. Sweet cherries: Lapins, one of the two hardiest sweet cherries we've found, and Rainier, which cracks where it rains at ripening and likes your dry summers. Apricot: Harlayne. Peaches: Contender, the only commercial peach we know of that has taken −32°F, and Blushingstar, which came through −25°F at our place on January 13, 2024 without damage. A 1959 University of Idaho bulletin put peach bud kill at about −13°F, so a hard winter can cost the crop even where the tree lives.

Twin Falls, Jerome, Kimberly, Hansen, Wendell and Hollister: −15°F to −17°F

Apples: Spartan, Liberty and Golden Russet. Pears: D'Anjou and Honeysweet; the University of Idaho's old bulletin paired Bartlett with Anjou as its pollenizer, and the pollination maps show what pollenizes what. Plums: Stanley and Mount Royal. Tart cherry: Montmorency. Peach: Siberian C, the hardiest peach we think is out there, though it ripens very late. Berries: Montana Black Currant and Red Lake currant, which fruited well for us in 2026 after flower buds saw about 22°F.

Eden, Murtaugh, Milner and the flats around Hazelton: −18°F to −20°F

Apples: Wealthy and Zestar!®, plus the applecrabs Kerr and Centennial (Ed Schultz saw zero winter injury on Centennial after a −47°F winter). Pear: Luscious. Plums: Toka and Superior; Toka pollenizes Superior. Tart cherry: Evan's Bali, good to at least −40°F. Apricot: Westcot, on a butte flank. Berries: Honeyberry for frost pockets like Greenwood and McHenry, and Invicta gooseberry. Out toward Owinza at −24°F, stick to this list.

Roots, soil and the local troubles

Dormant apple roots are seriously hurt near 10°F, and snow is thin here (about 24 inches a year at Twin Falls), so use the hardiest rootstock you can on bare or windswept ground and don't let the soil go into winter bone dry. Go easy on late nitrogen and late water, and use drip, the only irrigation we advise for fruit trees in dry country. Portneuf silt loam, a soil that's extensive across southern Idaho, carries a lime-cemented hardpan from about 14 inches down that passes water slowly and stops most roots, and its pH of about 7.8 to 8.4 brings iron chlorosis. Dig a hole 2 feet deep, fill it, let it drain, fill it again; under 10 hours is well drained. Guard trunks against voles and rabbits, keep nitrogen low on pears against fire blight, and paint trunks white against winter sun.

Fruit history here

The Magic Valley got its name from Milner and Minidoka dams and the canals built off the Snake in the first decade of the 1900s, which turned near-uninhabitable land into some of the Northwest's most productive farmland. I. B. Perrine founded the Twin Falls Land and Water Company in 1900, and Frank Buhl and Peter Kimberly, whom he introduced in 1901, formed the company that built the South Side Project. Orchards came early: Clarence Bisbee's photographs at the Twin Falls Public Library show a 40-acre commercial orchard near Kimberly around 1915 and Jonathan apples at the Polzin Orchard south of town. In 1959 the University of Idaho's Bulletin 300 put Twin Falls, Jerome, Kimberly, Wendell, Burley and Rupert in its fruit Zone 2 and said fruit belongs on ground with good air drainage.

Questions people ask

What growing zone is Twin Falls, Idaho?

Utah State's calculation from 1990 to 2019 station data puts Twin Falls in zone 6b, built on an average winter's coldest night (about −0.4°F). We plan for the bad night: Twin Falls plans for −15°F (MFTC 5a), Buhl −13°F (5b), and Eden, Murtaugh and Milner −18°F to −19°F (5a).

When is the last frost in Twin Falls?

NOAA station records put the median last 32°F at May 9 at the Twin Falls airport and May 10 east of town (1991 to 2020), and one year in ten it comes after June 3 east of town. The last 28°F, where open blossoms start dying, comes around April 19 to April 30. Buhl and Hagerman run about a week ahead.

Can you grow peaches in Twin Falls?

Yes. Kelley's Canyon Orchard has grown them since 1908. The trees aren't the problem (Contender has come through −30°F and Twin Falls plans for −15°F); the crop is, since April freezes took most of Kelley's crop in 2024 and half or more in 2026. Plant on your best spring ground, like Buhl's bench.

Can you grow sweet cherries in the Magic Valley?

Yes, on good spring ground. Lapins has come through −35°F and Rainier −30°F, well past the planning lows here. They bloom early, though, and Kelley's lost most of its cherries on April 17 and 18, 2026, so plant them where the spring layer reads even with Twin Falls or better.

Is the Snake River Canyon warmer than Twin Falls?

The family that has farmed the canyon floor since 1908 says it runs about 3°F warmer than the land around it, from the rock holding heat and the river. It still froze hard in April 2024 and 2026. Downstream, the Hagerman Valley floor plans for −16°F, 1°F colder than Twin Falls, but its median last frost comes about a week earlier.

Why are my fruit tree leaves turning yellow in Twin Falls?

Most likely iron chlorosis. Portneuf silt loam, extensive across southern Idaho, runs about pH 7.8 to 8.4, and the University of Idaho says chlorosis shows up at pH 7.5 and above, worse under heavy mulch or in lawn.

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.