What USDA hardiness zone is Johnson County, Missouri?

Every ZIP code in Johnson County, Missouri is USDA hardiness zone 6b, from the USDA 2023 Plant Hardiness Zone Map.

When is the last spring frost in Johnson County, Missouri?

The median last spring freeze runs April 13 – April 17 across the 4 NOAA weather stations serving Johnson County, Missouri, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

Missouri

Planting zones in Johnson County, Missouri

Every ZIP code in this county is USDA zone 6b — so unlike most of the places people look up, there is one right answer here and it holds wherever you are in the county.

USDA zone 6b The same in all 8 ZIP codes

ZIP codes 8 8 have a NOAA station within range

Weather stations 4 NOAA 1991–2020 normals, across 829 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Johnson County, Missouri as a whole. Hardiness zones and freeze dates are published per ZIP code, so yours is exact — enter it and this page will tell you your zone, which NOAA station it comes from and how far away that station is.

The growing season in Johnson County is closing

Nothing in the 32-crop table still has time to mature here. The first fall freeze normally arrives October 21 – October 23 across the 4 NOAA stations serving this county .

Your next season already has a date

The first job of it is 🧅 Green Onions, start indoors, around February 16 – February 20 — counted back from a last spring freeze of April 13 – April 17 here.

Every spring date for your ZIP →

These are ranges across the whole county. The ZIP lookup above gives the dates from your own nearest station instead.

All 4 stations agreeAt least one station

Every one of the 4 NOAA stations serving this county counts April 17 – October 21 as growing season (187 days). Widening to any single station gives April 13 – October 23 (193 days).

Your freeze dates

Last spring freeze April 13 – April 17

First fall freeze October 21 – October 23

Across the 4 NOAA stations serving this county. These are medians — half of years freeze later than the date shown — so treat the later end of each range as the cautious one.

The growing season runs 187–191 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 85.1–87.9 °F in June–August. Summer rain over the same months runs 13.0–15.2" across those 4 stations, against the rough inch a week — about 13 inches over the same 92 days — that a vegetable garden is usually reckoned to want. At the middle station that is covered, so watering in Johnson County is for the gaps between storms rather than the whole season. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 88 °F summer afternoon drying the soil faster than a cool one.

Every ZIP code in Johnson County

Zones are published per ZIP code, not per county, so this is the exact answer rather than the county's average. The station column is the nearest one to that ZIP code's centroid and how far away it is — the same figure the tools use, shown here so you can see which ZIP codes are well covered and which are reaching.

ZIP code	USDA zone	Nearest NOAA station	Distance
64019	6b	Warrensburg 4Nw, MO	5.6 km
64040	6b	Elm, MO	17.0 km
64061	6b	Elm, MO	10.0 km
64093	6b	Warrensburg 4Nw, MO	6.1 km
64733	6b	Clinton, MO	21.6 km
64761	6b	Windsor, MO	15.0 km
65305	6b	Warrensburg 4Nw, MO	22.2 km
65336	6b	Warrensburg 4Nw, MO	21.1 km

ZIP-code positions are area centroids, so a large rural ZIP code's listed distance is measured from the middle of its area rather than from any particular address in it.

When to start seeds in Johnson County

Every date below is anchored on the last spring freeze at each station and reported as a range across all 4 of them, because no one station speaks for the county.

Crop	Job	When	Offset
🧅 Green Onions	Start indoors	February 16 – February 20	8 wk before
🌶️ Peppers	Start indoors	February 16 – February 20	8 wk before
🥦 Broccoli	Start indoors	March 2 – March 6	6 wk before
🥬 Cabbage	Start indoors	March 2 – March 6	6 wk before
🥬 Collards	Start indoors	March 2 – March 6	6 wk before
🥬 Kale	Start indoors	March 2 – March 6	6 wk before
🥬 Leaf Lettuce	Start indoors	March 2 – March 6	6 wk before
🫛 Peas	Direct sow	March 2 – March 6	6 wk before
🥬 Spinach	Direct sow	March 2 – March 6	6 wk before
🍠 Sweet Potato	Start indoors	March 2 – March 6	6 wk before
🍅 Tomatoes	Start indoors	March 2 – March 6	6 wk before
🥬 Bok Choy	Start indoors	March 9 – March 13	5 wk before
🥬 Kohlrabi	Start indoors	March 9 – March 13	5 wk before
🥬 Swiss Chard	Start indoors	March 9 – March 13	5 wk before
🥬 Arugula	Direct sow	March 16 – March 20	4 wk before
🥬 Baby Salad Greens	Direct sow	March 16 – March 20	4 wk before
🥕 Beets	Direct sow	March 16 – March 20	4 wk before
🧅 Green Onions	Direct sow	March 16 – March 20	4 wk before
🥬 Mustard Greens	Direct sow	March 16 – March 20	4 wk before
🌶️ Okra	Start indoors	March 16 – March 20	4 wk before
🌱 Radishes	Direct sow	March 16 – March 20	4 wk before
🥔 Turnips	Direct sow	March 16 – March 20	4 wk before
🥬 Cabbage	Set out	March 23 – March 27	3 wk before
🥕 Carrots	Direct sow	March 23 – March 27	3 wk before
🥬 Collards	Direct sow	March 23 – March 27	3 wk before
🥬 Collards	Set out	March 23 – March 27	3 wk before
🥒 Cucumbers	Start indoors	March 23 – March 27	3 wk before
🧅 Green Onions	Set out	March 23 – March 27	3 wk before
🥬 Kale	Direct sow	March 23 – March 27	3 wk before
🥬 Kale	Set out	March 23 – March 27	3 wk before
🥬 Kohlrabi	Direct sow	March 23 – March 27	3 wk before
🥬 Kohlrabi	Set out	March 23 – March 27	3 wk before
🥬 Leaf Lettuce	Direct sow	March 23 – March 27	3 wk before
🎃 Pumpkins	Start indoors	March 23 – March 27	3 wk before
🎃 Summer Squash	Start indoors	March 23 – March 27	3 wk before
🎃 Winter Squash	Start indoors	March 23 – March 27	3 wk before
🥒 Zucchini	Start indoors	March 23 – March 27	3 wk before
🥬 Bok Choy	Direct sow	March 30 – April 3	2 wk before
🥬 Bok Choy	Set out	March 30 – April 3	2 wk before
🥦 Broccoli	Set out	March 30 – April 3	2 wk before
🌿 Cilantro	Direct sow	March 30 – April 3	2 wk before
🥬 Leaf Lettuce	Set out	March 30 – April 3	2 wk before
🥬 Swiss Chard	Direct sow	March 30 – April 3	2 wk before
🥬 Swiss Chard	Set out	March 30 – April 3	2 wk before
🌿 Dill	Direct sow	April 6 – April 10	1 wk before
🫘 Bush Beans	Direct sow	April 20 – April 24	1 wk after
🥒 Cucumbers	Set out	April 20 – April 24	1 wk after
🎃 Pumpkins	Direct sow	April 20 – April 24	1 wk after
🎃 Pumpkins	Set out	April 20 – April 24	1 wk after
🎃 Summer Squash	Direct sow	April 20 – April 24	1 wk after
🎃 Summer Squash	Set out	April 20 – April 24	1 wk after
🌽 Sweet Corn	Direct sow	April 20 – April 24	1 wk after
🍅 Tomatoes	Set out	April 20 – April 24	1 wk after
🎃 Winter Squash	Direct sow	April 20 – April 24	1 wk after
🎃 Winter Squash	Set out	April 20 – April 24	1 wk after
🥒 Zucchini	Direct sow	April 20 – April 24	1 wk after
🥒 Zucchini	Set out	April 20 – April 24	1 wk after
🥒 Cucumbers	Direct sow	April 27 – May 1	2 wk after
🌶️ Okra	Direct sow	April 27 – May 1	2 wk after
🌶️ Okra	Set out	April 27 – May 1	2 wk after
🌶️ Peppers	Set out	April 27 – May 1	2 wk after
🫘 Southern Peas	Direct sow	April 27 – May 1	2 wk after
🍠 Sweet Potato	Set out	April 27 – May 1	2 wk after

Offsets are published guidance; the dates they land on are computed from measured NOAA normals. The seed-starting tool does this for your own ZIP code and counts the days.

What lives through a zone 6b winter

Of 74 perennial edibles, 51 come through a zone 6b winter — and 0 fail here for being too warm rather than too cold, needing more winter chill than this county gets or more heat than they tolerate. Among the ones that work: Cranberry, Honeyberry, Lingonberry, Apple, Aronia, Black Currant, Elderberry, Gooseberry.

Hardiness ranges are a judgement, published by growers rather than measured; the zone they are compared against is measured. On a warm-end verdict, check with your local extension service — a coastal zone 8 and an inland zone 8 are not the same summer.

Cautious — shortens the seasonMedian across stationsOptimistic

Last spring freeze: Plan to May 4 to be careful. Median April 13 – April 17 across 4 stations; March 30 is the optimistic end.
First fall freeze: Plan to October 6 to be careful. Median October 21 – October 23 across 4 stations; November 3 is the optimistic end.

NOAA publishes these as probabilities, not averages — the middle figure is a median, so half of years fall either side of it. The cautious end is the 10% tail: in roughly nine years in ten the freeze falls on the safe side of it.

The 4 stations behind these numbers

All 4 NOAA stations whose normals this page quotes, spanning about 53 km north to south. Every one is named with its identifier in the station list below — this page does not single one out, because no one station speaks for a whole county.

A relative sketch, not a map with a projection: longitude is adjusted for latitude so the shape is not stretched, and there is no basemap. For the one station nearest a specific address, with its real distance, use the ZIP lookup above.

These are the stations this county's ZIP codes actually cite as nearest — not a claim that each one sits inside its boundary, since a rural ZIP legitimately reaches over it. Every figure above comes from them, and each is named so you can check it.

Station	NOAA ID	Last spring freeze	First fall freeze	Season
Clinton, MO	USC00231711	April 17	October 21	187 days
Elm, MO	USC00232568	April 13	October 23	191 days
Warrensburg 4Nw, MO	USC00238712	April 14	October 21	189 days
Windsor, MO	USC00239034	April 13	October 22	191 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Your own ZIP

Work out your own dates

This page describes a whole county. Every tool below answers for one ZIP code, which is the grain the underlying data is published at.

Other places to compare

Johnson County sits in Missouri. That page carries the whole state's zone spread, its metro areas, and every other county in it with a page here.

More of Missouri

Counties with the same zones — 6b

Matched on the exact zone set, not a dominant zone, so the winter answer on these pages really is the same one as here.

Gear

If you want to act on this

Each link opens an Amazon search rather than a product we picked. We have not tested these and do not rank them — the search is the honest version, and you choose.

Row cover and frost clothThe season here closes at the first fall freeze dated above — a cover buys back some of those days at the end.
MulchFor the perennials nearest their cold limit in zone 6b, where an insulated crown is what decides whether they come back.

As an Amazon Associate we earn from qualifying purchases. That costs you nothing extra, and it buys no influence over anything on this site: the dates come from NOAA normals and the zones from the USDA, and no product affects either.

Sources

Where these numbers come from

Hardiness zones are the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. Freeze dates and growing-season lengths are NOAA 1991–2020 Climate Normals, taken per station and cited above by name and NOAA ID.

County boundaries come from the Census ZCTA-to-county relation, which is what places each ZIP code — and which treats parishes, boroughs and census areas as county equivalents. No station is chosen to represent this county: every range above is taken across all of them and the count is stated, because picking one would be a judgement dressed as a measurement.