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

Planting zone for 65778 — Myrtle, MO

ZIP code 65778 (Myrtle, Oregon County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 17 and the first fall frost October 21.

Where ZIP 65778 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.

Zone7a0 to 5 °F

Coldest night−17.8 to −15 °C

Last frostApr 17

First frostOct 21

2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Myrtle, MO…

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 Myrtle, MO

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 1only 10% chance of frost after

First fall frostOctober 21median — 10% chance by Oct 7

Growing season187 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around October 30.

From the NOAA station Alton, MO — 13 miles away, elevation 814 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 65778

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 · Aug 26 – Sep 9

GarlicPlant cloves · Oct 7 – Nov 11

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 17) and first fall frost (Oct 21) 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 65778 came on Feb 24 — 9 days earlier than the 1991–2020 average (Mar 5).

average
Mar 52026
Feb 24

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 7a in Missouri

540 plants native to the lower 48 states, recorded in Missouri, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. 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 Myrtle, MO.

Soil in Myrtle, MO

The soil mapped at the center of ZIP 65778 is Alred — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer

pH4.3strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter69%high

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Alred-Gatewood complex, 1 to 8 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 65778; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Myrtle, MO

Summer high88 °Faverage high, July

Winter low22 °Faverage low, January

Hot days48days a year at 90 °F or more

Freezing nights110nights a year at 32 °F or less

Growing degree days3,981base 50 °F — the season’s usable heat

Longest day14 h 39 mindaylight on June 21

Shortest day9 h 40 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation47.2 inper year, rain and melted snow

Snowfall4 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Alton, MO (13 mi away); precipitation: Alton, MO (13 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Warm Springs, AR · 13 mi

657917a

Thayer, MO · 13 mi

724607b

Ravenden Springs, AR · 14 mi

725547a

Mammoth Spring, AR · 17 mi

724597b

Ravenden, AR · 18 mi

Missouri planting zones →

Questions about 65778

What planting zone is ZIP code 65778?

ZIP code 65778 (Myrtle, MO) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Myrtle, MO?

The median last spring frost (32 °F) near 65778 is April 17; after May 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Alton station.

When is the first frost in Myrtle, MO?

The median first fall frost near 65778 is October 21, giving a median frost-free growing season of 187 days.

When should I plant tomatoes in 65778?

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 65778 get?

About 47.2 inches of precipitation a year and 4 inches of snowfall (NOAA 1991–2020 normals, Alton station).

How hot do summers get in Myrtle, MO?

The average high peaks at 88 °F in July, with about 48 days a year at 90 °F or more.

What kind of soil does 65778 have?

The USDA soil survey maps Alred at the center of ZIP 65778: slightly decomposed plant material, well drained, pH about 4.3 (strongly acidic).

Did spring come early in Myrtle, MO in 2026?

Spring leaf-out near 65778 came on Feb 24 in 2026, 9 days earlier than the 1991–2020 average (Mar 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Myrtle, MO?

Intermediate onions: the longest day near 65778 is 14 h 39 min, so day-neutral types bulb best; long-day varieties may not bulb fully.