Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 49090 — South Haven, MI

ZIP code 49090 (South Haven, Van Buren County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 17 and the first fall frost November 5.

Where ZIP 49090 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 17
First frostNov 5
2012 zone6b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for South Haven, MI…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in South Haven, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 17median — 50% chance of a later frost
Safe for tender plantsMay 4only 10% chance of frost after
First fall frostNovember 5median — 10% chance by Oct 24
Growing season201 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 14.

From the NOAA station S Haven, MI — 4 miles away, elevation 591 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 49090

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 6 – Mar 20
SpinachSow outdoors · Mar 6 – Mar 27
Broccoli, cabbageStart indoors · Feb 6 – Feb 20
Broccoli, cabbageTransplant · Mar 27 – Apr 10
Onion setsPlant outdoors · Mar 20 – Apr 3
PotatoesPlant outdoors · Mar 27 – Apr 10
LettuceSow outdoors · Mar 20 – Apr 3
Carrots, beetsSow outdoors · Mar 27 – Apr 10
TomatoesStart indoors · Feb 20 – Mar 6
TomatoesTransplant · Apr 24 – May 8
Peppers, eggplantStart indoors · Feb 6 – Feb 20
Peppers, eggplantTransplant · May 1 – May 15
BeansSow outdoors · Apr 24 – May 8
Sweet cornSow outdoors · Apr 24 – May 8
Cucumbers, squashSow outdoors · Apr 24 – May 8
Fall lettuce, spinachSow outdoors · Sep 10 – Sep 24
GarlicPlant cloves · Oct 22 – Nov 26
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 17) and first fall frost (Nov 5) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 49090 came on Mar 30 — 10 days earlier than the 1991–2020 average (Apr 9).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 6b in Michigan

582 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 58

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 105

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 221

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °F

Grasses 175

alpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 8

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in South Haven, MI.

Soil in South Haven, MI

The soil mapped at the center of ZIP 49090 is Houghton — muck, very poorly drained.

TextureMucktop layer
DrainageVery poorly drainedconsider raised beds
Organic matter76.2%high
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classFarmland of local importanceUSDA classification

Map unit: Houghton muck, lake moderated, 0 to 1 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 49090; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in South Haven, MI

Summer high80 °Faverage high, July
Winter low22 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights108nights a year at 32 °F or less
Growing degree days2,980base 50 °F — the season’s usable heat
Longest day15 h 17 mindaylight on June 21
Shortest day9 h 04 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation37.2 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 34 °F, low 22 °F 34°22° JanFebruary: average high 36 °F, low 24 °F 36°24° FebMarch: average high 45 °F, low 30 °F 45°30° MarApril: average high 56 °F, low 39 °F 56°39° AprMay: average high 68 °F, low 49 °F 68°49° MayJune: average high 76 °F, low 60 °F 76°60° JunJuly: average high 80 °F, low 66 °F 80°66° JulAugust: average high 79 °F, low 64 °F 79°64° AugSeptember: average high 74 °F, low 57 °F 74°57° SepOctober: average high 62 °F, low 48 °F 62°48° OctNovember: average high 49 °F, low 36 °F 49°36° NovDecember: average high 39 °F, low 28 °F 39°28° Dec

Precipitation by month inches

0″1″2″3″4″January: 2.71 in precipitation 2.7 JanFebruary: 2.04 in precipitation 2.0 FebMarch: 2.25 in precipitation 2.3 MarApril: 3.58 in precipitation 3.6 AprMay: 3.91 in precipitation 3.9 MayJune: 3.73 in precipitation 3.7 JunJuly: 3.16 in precipitation 3.2 JulAugust: 3.70 in precipitation 3.7 AugSeptember: 3.19 in precipitation 3.2 SepOctober: 3.89 in precipitation 3.9 OctNovember: 2.68 in precipitation 2.7 NovDecember: 2.38 in precipitation 2.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: S Haven, MI (4 mi away); precipitation: S Haven, MI (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

4 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

490636b
Lacota, MI · 4 mi
490566a
Grand Junction, MI · 8 mi
494166b
Glenn, MI · 8 mi
490276a
Breedsville, MI · 8 mi
494506a
Pullman, MI · 9 mi
490436b
Covert, MI · 9 mi
490136a
Bangor, MI · 9 mi
494086b
Fennville, MI · 12 mi

Michigan planting zones →

Questions about 49090

What planting zone is ZIP code 49090?

ZIP code 49090 (South Haven, MI) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in South Haven, MI?

The median last spring frost (32 °F) near 49090 is April 17; after May 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, S Haven station.

When is the first frost in South Haven, MI?

The median first fall frost near 49090 is November 5, giving a median frost-free growing season of 201 days.

When should I plant tomatoes in 49090?

Start tomato seeds indoors around Feb 20 – Mar 6 and set transplants outside around Apr 24 – May 8, one to three weeks after the median last frost.

How much rain and snow does 49090 get?

About 37.2 inches of precipitation a year (NOAA 1991–2020 normals, S Haven station).

How hot do summers get in South Haven, MI?

The average high peaks at 80 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 49090 have?

The USDA soil survey maps Houghton at the center of ZIP 49090: muck, very poorly drained.

Did spring come early in South Haven, MI in 2026?

Spring leaf-out near 49090 came on Mar 30 in 2026, 10 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in South Haven, MI?

Long-day onions: the longest day near 49090 is 15 h 17 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).