zucchini (Cucurbita pepo), photographi

Can I Grow Zucchini in Wyoming?

USDA Zones 3b-6a · Plant zone range 2-11

Yes — Strong Match

zucchini (zones 2-11) covers every zone Wyoming contains (3b-6a), so hardiness is not what limits it anywhere in the state.

Zucchini in Wyoming — the short answer

Zucchini in Wyoming: hardy in zones 2–11, full sun, against a state median of ~151 frost-free days.

Plant zones
2-11
Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
Wyoming zones
3b-6a
USDA PHZM 2023
Frost window
May 4 - May 13 – Sep 30 - Oct 7
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
79 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Days to maturity
55 days
Growable Ground Plant Database

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free

Your yard isn't the whole zone.

Zucchini is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Wyoming site runs ~151 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score zucchini against your land's actual frost dates, sun, and soil.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

Wyoming is not one climate

A single Wyoming answer averages 23 counties whose growing seasons are 87 days apart — from 79 frost-free days in Teton County to 166 in Big Horn County. Which end of that your land sits nearer changes what zucchini can finish before the first hard freeze.

79 daysTeton County166 daysBig Horn County

The middle half of 23 counties runs 136155 days, with a median of 151 days — a 87-day span end to end.

Measured across 23 Wyoming counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where in Wyoming Fits Best

Even within Wyoming's zones 3b-6a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for zucchini (USDA PHZM 2023):

Zone Comparison

Zucchini Needs

  • USDA Zones: 2-11
  • Frost-Free Days: 40+
  • Sun: Full Sun
  • Mature size: 3 ft tall
  • Picking window: ~35 days of harvest
  • Drought tolerance: Medium

Wyoming Has

  • USDA Zones: 3b-6a
  • Last Hard Freeze (28°F): May 4 - May 13
  • First Hard Freeze (28°F): Sep 30 - Oct 7
  • Annual Rainfall: 6-20 inches
  • Common Soils: Sandy loam, Clay, Alkaline

Plant Zone Range (zones 2-11)

2a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.58.3

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Zucchini in Wyoming

The frost window

Across Wyoming, the last spring hard freeze (28°F) clears between May 4 and May 13, and the first fall hard freeze lands between Sep 30 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 140-day window you can count on — up to 156 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

When to start the seed

Those dates are when zucchini goes out, not when it starts. It is sown under cover about 3 weeks ahead, so counting back from Wyoming's late-side last freeze of May 13 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Days to maturity vs. the window

At 55 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 85 days to spare even in Wyoming's tightest freeze scenario — room for a later start or a second sowing.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

The zone check says zucchini survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Zucchini wants 40+ frost-free days; a typical Wyoming site sees ~151 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

Growing degree days

Zucchini needs ~1100 GDD (base 50°F) to ripen. The state median runs ~1866 GDD (from PRISM 1991-2020 climate normals), so Wyoming's typical season clears that easily.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Zucchini tolerates a wide pH range (pH 4.5-8.3) — 3.8 units, acid ground through alkaline — so soil acidity is rarely what limits it in Wyoming. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 5.5 and 6.8 — worth knowing before you decide whether a Wyoming soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Wyoming site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Wyoming soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant zucchini for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before zucchini goes in. What follows is Wyoming’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Wyoming — and how to grow with it.

Federal record: High

We checked the federal record across Wyoming10,910 documented sites across 8 of the 9 source types we track.

The most significant on record: 64 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Wyoming carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Severity Distribution

across Wyoming

High42Moderate5,938Low4,930

Highest-Severity Sites

B&H Mining Company
Mining Sites · Past Producer
Baxter/Union Pacific Tie Treating
Superfund · Superfund NPL
Black Thunder Coal Mine
PFAS Sampling · PFAS Detected
Black Butte Deposit
Mining Sites · Past Producer
Bridger Mine
Mining Sites · Past Producer

A note from Gnorman

What an experienced grower watches for around here

In and around Wyoming, Nitrate runs higher than the national average — 4,750 sites across Wyoming. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.

Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.

Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Zucchini in Wyoming

Zone compatibility tells you about winter cold survival — but Wyoming growers also need to think about:

Extremely short growing season (60-90 frost-free days)

Very low rainfall requires irrigation

Persistent high winds desiccate and damage plants

What to actually do about these — and the constraints that apply to every Wyoming grower, not just zucchini — is covered on the Wyoming growing guide.

Timing shifts within Wyoming

Zucchini needs about 40 days of frost-free season to complete its cycle. Even Teton County — Wyoming’s shortest season at 79 frost-free days — clears that by 39 days, so season length isn’t the constraint anywhere in Wyoming. What varies is your own parcel.

Across Wyoming’s 23 counties the frost-free season runs from 79 days in Teton County to 166 days in Big Horn County — a spread of 87 days, which is why a single statewide planting date misleads. The median Wyoming county sees 151 frost-free days, leaving zucchini about 111 days of slack on a typical parcel — room for a second sowing where the season runs long.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Zucchini's 40-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Pollinator + Wildlife Value

Zucchini draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, zucchini can only work that bloom inside Wyoming's frost window — roughly 151 days, opening after the last 28°F freeze (May 4 - May 13) and closing at the first (Sep 30 - Oct 7), per NOAA Regional Climate Centers ACIS, 1991-2020.

Wyoming Cooperative Extension

For Wyoming-specific cultivar recommendations, planting calendars, and pest pressure for zucchini, the canonical source is University of Wyoming Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Zucchini native to Wyoming?

No — the USDA PLANTS Database lists Zucchini as introduced rather than native in the Lower 48, so it is not part of Wyoming's native flora. It grows here as a garden plant; pairing it with a few Wyoming natives keeps local pollinators fed too.

Looking for plants that belong here? The Wyoming growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

What pests threaten zucchini in Wyoming?

Squash bug is documented in Wyoming, and it hits zucchini where it counts. Here is what it actually does — and the move that beats it.

Squash bug

Squash bug

Act on this

Squash bugs primarily attack squash and pumpkins, and the plants most at risk are the youngest and the ones in flower — the University of Minnesota notes feeding can kill young plants outright, while a larger, sturdier plant shrugs it off.

What to do: Go after where they sleep, not just the bugs. Crush the bronze egg clusters on the leaf undersides in the vein angles, drop nymphs and adults into soapy water, and clear plant debris through the season and again in fall to strip out overwintering shelter. Where squash bugs are a consistent problem, skip straw mulch — it gives them the night shelter they are looking for.

Here: In Wyoming that second clean-up lands around Sep 30 - Oct 7, when the first 28°F freeze typically ends the zucchini — pulling the vines then is what strips the overwintering shelter, and leaving them is what stocks next season.

Documented range: the United States · University of Minnesota Extension, University of Illinois IPM, University of Kentucky Entomology

The full squash bug playbook

Only pests whose documented range and host relationship both trace to a primary source appear here — so a quiet section means we have nothing sourced to tell you, not that your garden is pest-free.

Common Questions About Growing Zucchini in Wyoming

When can I plant Zucchini in Wyoming?

Wyoming's last spring hard freeze (28°F) clears between May 4 and May 13, and the first fall hard freeze lands between Sep 30 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.

Can Zucchini mature before first frost in Wyoming?

Yes — Zucchini matures in 55 days (Growable Ground Plant Database), and Wyoming's dependable hard-freeze-free window runs 140 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 85 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.

What hardiness zone is Zucchini grown in across Wyoming?

Wyoming spans USDA hardiness zones 3b-6a (USDA ARS PHZM 2023). Zucchini carries a range of zones 2-11, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Wyoming site have?

A typical Wyoming site sees ~151 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Zucchini needs 40+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Zucchini native to Wyoming?

No — the USDA PLANTS Database lists Zucchini as introduced rather than native in the Lower 48, so it is not part of Wyoming's native flora. It grows here as a garden plant; pairing it with a few Wyoming natives keeps local pollinators fed too.

How should I amend the soil for Zucchini in Wyoming?

Zucchini tolerates pH 4.5-8.3 and well (dry spells) drainage (FAO ECOCROP). That is a 3.8-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Wyoming site — amend for drainage and organic matter first.

Will Zucchini actually grow on my specific land in Wyoming?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores zucchini against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Wyoming

State-level data is a sketch. Your Growable Ground report scores zucchini against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Wyoming zucchini averages can't show:

Your soil pHYour frost-free days — Wyoming averages 151Your sun & shade

We read public map data around Wyoming — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Wyoming zucchini average

Last updated: