What does USDA hardiness zone 6b mean in New Mexico?

Zone 6b means an average annual extreme minimum winter temperature of −5 to 0 °F — the standard USDA measure of which perennials survive winter. 31 locations in New Mexico fall in this zone. It does not set planting dates; see the frost calendar below for that.

Where in New Mexico's zone 6b is the growing season longest?

Blanco runs the longest season on this page at about 177 days; Coyote is shortest at about 83 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.

When should I plant tomatoes in New Mexico's zone 6b?

Using Encino's frost dates (this page's median-season location): start seeds indoors about Mar 14 – Mar 28, then transplant outside about May 16 – May 23. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.

Does every location in New Mexico's zone 6b have the same frost dates?

No — they do not all share a weather station, so frost dates vary by a week or more across the 31 locations listed (see the table above for each location's own dates).

USDA zone 6b in New Mexico

−5 to 0 °F avg. annual extreme minimum · 31 locations in this group · NOAA 1991–2020 normals

USDA plant hardiness zone 6b covers 31 locations across New Mexico (average annual extreme minimum −5 to 0 °F): Blanco, NM, Brimhall Nizhoni, NM, Clayton, NM, Coyote, NM, Des Moines, NM, Des Moines, NM, and 25 more. Average last spring frost across this group ranges April 23 (Blanco) to June 19 (Coyote), and growing seasons run 83–177 days (Coyote to Blanco) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every New Mexico location's own frost dates; the printable planting calendar uses Encino, this group's median-season location.

USDA zone: 6b−5 to 0 °F
Last frost range: Apr 23–Jun 19avg, 32°F
First frost range: Sep 13–Oct 20avg, 32°F
Growing season range: 83–177days

Locations in this group

Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.

Own frost dates per location.
Location	Also covers	Nearest station	Last frost	First frost	Season (days)
Blanco	—	Bloomfield 3 Se	Apr 23	Oct 19	177
Brimhall Nizhoni	Pinedale, Twin Lakes, Nakaibito, Gamerco	Gallup Muni Ap	May 31	Sep 28	119
Clayton	Texline	Clayton Muni Air Pk	Apr 27	Oct 17	170
Coyote	—	Wolf Canyon	Jun 19	Sep 13	83
Des Moines	Pritchett	Kim 10sse	Apr 24	Oct 18	175
Des Moines	—	Grenville	May 5	Oct 9	156
Encino *	—	Pedernal 9 E	May 9	Oct 6	150
Gallina	Youngsville	Abiquiu Dam	Apr 29	Oct 16	168
Grenville	—	Pasamonte	May 5	Oct 7	153
La Cueva	—	Jemez Springs	May 9	Oct 11	153
La Cueva	Rowe, East Pecos, Galisteo, North San Ysidro	Pecos Nm	May 15	Oct 3	138
La Madera	—	Tres Piedras	May 31	Sep 28	118
La Madera	—	El Rito	May 15	Oct 7	143
La Plata	Center Point, Flora Vista	Aztec Ruins Nm	May 12	Oct 6	147
Laguna	Skyline-Ganipa, Paraje, Paguate, San Fidel	Cubero	May 13	Oct 4	145
Las Vegas	Mora	Gascon	May 28	Sep 26	119
Las Vegas	Mora	Las Vegas Muni Ap	May 10	Oct 7	149
Manzano	—	Mountainair	May 2	Oct 19	167
Mosquero	—	Mosquero 1 Ne	May 3	Oct 12	160
Nageezi	Becenti	Chaco Canyon Natl Mon	May 28	Sep 27	120
Nara Visa	Texline	Amistad 5 Ssw	Apr 27	Oct 17	172
Ojo Sarco	Cordova	Alcalde	May 10	Oct 4	145
Roy	—	Roy	Apr 30	Oct 15	167
Santa Fe Foothills	Hyde Park	Santa Fe 2	May 14	Oct 6	144
Stanley	—	Stanley 2 Nne	May 9	Oct 7	150
Stanley	Pueblo	Clines Corners	May 4	Oct 12	159
Tecolotito	—	Dilia	May 2	Oct 13	162
Thunder Mountain	—	Moriarty 1 Ne	May 14	Oct 4	142
Tse Bonito	Sawmill	Window Rock Ap	May 29	Sep 28	121
Villanueva	Sena	Villanueva	Apr 24	Oct 20	176
Willard	—	Estancia 4n	May 18	Oct 1	135

* Encino is this group's median-season location — the calendar below is computed from its data.

Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.

Planting calendar (Encino, representative)

Computed from Encino's average frost dates — the median-season location in this New Mexicozone 6b group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).

Crop

JanFebMarAprMayJunJulAugSepOctNovDec

Tomato

Pepper

Cucumber

Summer squash / zucchini

Start indoors
Plant out
Fall sowing
First harvest

Planting windows for Encino (New Mexico, zone 6b), this group's representative location.
Crop	Frost tolerance	Start indoors	Plant out	First harvest	Fall planting	Season fit
Tomato	Tender	Mar 14 – Mar 28	May 16 – May 23	Jul 15 – Aug 4	—	matures comfortably
Pepper	Very tender	Feb 28 – Mar 14	May 23 – May 30	Jul 22 – Aug 21	—	matures comfortably
Cucumber	Tender	Apr 11 – Apr 18	May 16 – May 23	Jul 5 – Jul 25	—	matures comfortably
Summer squash / zucchini	Tender	—	May 16 – May 23	Jun 30 – Jul 15	—	matures comfortably
Bush bean	Tender	—	May 16 – May 23	Jul 5 – Jul 15	Aug 7 – Aug 17	matures comfortably
Sweet corn	Tender	—	May 9 – May 23	Jul 8 – Aug 7	—	matures comfortably
Basil	Very tender	Mar 28 – Apr 11	May 16 – May 23	Jun 15 – Jun 30	—	matures comfortably
Lettuce	Half-hardy	Mar 28 – Apr 11	Apr 11 – Apr 25	May 26 – Jun 10	Jul 24 – Aug 8	matures comfortably
Pea	Hardy	—	Mar 28 – Apr 11	May 22 – Jun 6	Jul 14 – Jul 29	matures comfortably
Spinach	Hardy	—	Mar 28 – Apr 11	May 7 – May 17	Aug 3 – Aug 13	matures comfortably
Carrot	Half-hardy	—	Apr 18 – Apr 25	Jun 17 – Jul 7	Jul 4 – Jul 24	matures comfortably
Broccoli	Half-hardy	Mar 14 – Mar 28	Apr 11 – Apr 25	Jun 5 – Jun 25	Jul 9 – Jul 29	matures comfortably

Which crops fit this growing season

Using Encino's own 150-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.

Frost & freeze dates (Encino)

From NOAA's 1991–2020 Climate Normals at station USC00296687. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.

Freeze probabilities by temperature threshold (MM/DD, NOAA 1991–2020), Encino.
Threshold	Last spring — avg	Last spring — 90%-safe	First fall — avg	First fall — 90%-safe	Season (days)
36°F	May 19	May 31	Sep 30	Oct 12	132
32°F (freeze)	May 9	May 22	Oct 6	Oct 20	150
28°F	Apr 30	May 12	Oct 16	Nov 1	167
24°F	Apr 18	May 3	Oct 27	Nov 8	188

Growing degree days

Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 31 locations is 2,774; Encino's own reading is shown below.

Annual growing degree days for Encino (°F·days, NOAA 1991–2020).
Model	°F·days	Used for
Base 50°F (warm-season)	2,845	standard warm-season base (tomato, corn, beans)
Base 40°F (cool-season)	5,162	cool-season crops (brassicas, greens)

Hardiness zone 6b in New Mexico

Zone 6b means an average annual extreme minimum winter temperature of about −5 to 0 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. New Mexico spans 8 hardiness zones in this dataset — see all New Mexico locations for the full range, including zones5a, 5b, 6a, 7a, 7b, 8a, 8b.

Explore zone 6b in other states at zone 6b, or see all USDA hardiness zones.

Frequently asked questions

What does USDA hardiness zone 6b mean in New Mexico?: Zone 6b means an average annual extreme minimum winter temperature of −5 to 0 °F — the standard USDA measure of which perennials survive winter. 31 locations in New Mexico fall in this zone. It does not set planting dates; see the frost calendar below for that.
Where in New Mexico's zone 6b is the growing season longest?: Blanco runs the longest season on this page at about 177 days; Coyote is shortest at about 83 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
When should I plant tomatoes in New Mexico's zone 6b?: Using Encino's frost dates (this page's median-season location): start seeds indoors about Mar 14 – Mar 28, then transplant outside about May 16 – May 23. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
Does every location in New Mexico's zone 6b have the same frost dates?: No — they do not all share a weather station, so frost dates vary by a week or more across the 31 locations listed (see the table above for each location's own dates).

Sources & method

Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.