Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 48738 — Greenbush, MI

ZIP code 48738 (Greenbush, Alcona County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 8 and the first fall frost October 16.

Where ZIP 48738 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.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostMay 8

First frostOct 16

2012 zone5b

Was 5b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Greenbush, 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 Greenbush, MI

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 8median — 50% chance of a later frost

Safe for tender plantsMay 24only 10% chance of frost after

First fall frostOctober 16median — 10% chance by Oct 2

Growing season160 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 27 and returns around October 29.

From the NOAA station Harrisville 2nne, MI — 9 miles away, elevation 584 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 48738

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 27 – Apr 10

SpinachSow outdoors · Mar 27 – Apr 17

Broccoli, cabbageStart indoors · Feb 27 – Mar 13

Broccoli, cabbageTransplant · Apr 17 – May 1

Onion setsPlant outdoors · Apr 10 – Apr 24

PotatoesPlant outdoors · Apr 17 – May 1

LettuceSow outdoors · Apr 10 – Apr 24

Carrots, beetsSow outdoors · Apr 17 – May 1

TomatoesStart indoors · Mar 13 – Mar 27

TomatoesTransplant · May 15 – May 29

Peppers, eggplantStart indoors · Feb 27 – Mar 13

Peppers, eggplantTransplant · May 22 – Jun 5

BeansSow outdoors · May 15 – May 29

Sweet cornSow outdoors · May 15 – May 29

Cucumbers, squashSow outdoors · May 15 – May 29

Fall lettuce, spinachSow outdoors · Aug 21 – Sep 4

GarlicPlant cloves · Oct 2 – Nov 6

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 16) 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 48738 came on Apr 18 — 4 days earlier than the 1991–2020 average (Apr 22).

average
Apr 222026
Apr 18

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 6a in Michigan

580 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

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 Greenbush, MI.

Soil in Greenbush, MI

The soil mapped at the center of ZIP 48738 is Battlefield — sand, somewhat poorly drained.

TextureSanddrains and warms fast; dries out and needs more feeding

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter2%moderate

Hydrologic groupA/Ddrains fast once dried out; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Battlefield sand, 0 to 3 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 48738; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Greenbush, MI

Summer high74 °Faverage high, July

Winter low13 °Faverage low, February

Hot days3days a year at 90 °F or more

Freezing nights150nights a year at 32 °F or less

Growing degree days1,682base 50 °F — the season’s usable heat

Longest day15 h 33 mindaylight on June 21

Shortest day8 h 49 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation29.1 inper year, rain and melted snow

Snowfall52 inper year; 94 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Harrisville 2nne, MI (9 mi away); precipitation: Harrisville 2nne, MI (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

487455b

Mikado, MI · 7 mi

487405b

Harrisville, MI · 8 mi

East Tawas, MI · 16 mi

487216a

Black River, MI · 17 mi

487375a

Glennie, MI · 19 mi

487055a

Barton City, MI · 19 mi

Michigan planting zones →

Questions about 48738

What planting zone is ZIP code 48738?

ZIP code 48738 (Greenbush, MI) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Greenbush, MI?

The median last spring frost (32 °F) near 48738 is May 8; after May 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Harrisville 2nne station.

When is the first frost in Greenbush, MI?

The median first fall frost near 48738 is October 16, giving a median frost-free growing season of 160 days.

When should I plant tomatoes in 48738?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 48738 get?

About 29.1 inches of precipitation a year and 52 inches of snowfall (NOAA 1991–2020 normals, Harrisville 2nne station).

How hot do summers get in Greenbush, MI?

The average high peaks at 74 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 48738 have?

The USDA soil survey maps Battlefield at the center of ZIP 48738: sand, somewhat poorly drained, pH about 5.3 (strongly acidic).

Did spring come early in Greenbush, MI in 2026?

Spring leaf-out near 48738 came on Apr 18 in 2026, 4 days earlier than the 1991–2020 average (Apr 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Greenbush, MI?

Long-day onions: the longest day near 48738 is 15 h 33 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 48738 change?

Yes. The 2012 USDA map put 48738 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.