Wyoming planting calendar

When to plant cantaloupe in Wyoming — sow, transplant & harvest dates

Wyoming is mostly USDA zone 4b (range 3a-6a). Dates below are derived from cantaloupe's frost tolerance and Wyoming's frost window — not generic national averages.

Cantaloupe planting timetable for Wyoming

Stage	When in Wyoming	Anchor
Start seeds indoors	early May (May 4)	3 weeks before the last frost (late May)
Transplant outside	early June (June 8)	14 days after the last frost (late May)
First harvest (estimate)	late August (August 27)	~80 days from transplant

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why Wyoming's climate shifts the cantaloupe dates

Wyoming's last spring frost averages late May and first fall frost mid-September, which sets the whole planting clock. Wyoming is a high, cold, short-season state. Altitude and wind matter as much as the winter low; frost can come in any summer month at elevation. Wait for warm soil — cantaloupe stall in cold ground even after the air warms, so don't rush them out.

Cantaloupe (muskmelon) is one of the most heat-demanding cucurbits — soil temperature must reach 21 °C (70 °F) and night air temperatures should stay consistently above 15 °C before transplanting. Short-season zones 3-5 should start indoors 2-3 weeks early and use black plastic mulch to boost soil heat. Fruits ripen only in warm, dry conditions; humid climates favor powdery mildew and fruit rot, so zones 8-10 with hot summers are ideal. Withhold irrigation in the final 1-2 weeks before harvest to concentrate sugars.

Frost-risk note

Don't plant before late May — even a light frost will kill seedlings overnight. In the high mountain basins like Jackson Hole (zone 3a) the safe date runs a week or two later.

Regional variation within Wyoming

the high mountain basins like Jackson Hole (zone 3a) runs roughly 1-2 weeks behind the state average; the lower southeast plains near Cheyenne (zone 6a) can plant 1-2 weeks earlier.

Cheyenne — USDA zone 5b
Casper — USDA zone 5a
Jackson — USDA zone 4a
Sheridan — USDA zone 5a

What else to plant in Wyoming around then

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Quick-grow guide

Sun: Full sun — 6-8 hours direct.
Soil temperature for germination: 24-32 °C (75-90 °F).
Spacing: 36-48 inches (90-120 cm) between plants.
Days to harvest: ~80 days from planting out.

Frequently asked questions

When is the best time to plant cantaloupe in Wyoming?

In Wyoming (mostly USDA zone 4b), sow cantaloupe indoors around early May, transplant outdoors early June (after the last frost, late May), and harvest from late August. Cantaloupe are frost-tender — a single light frost kills seedlings, so they only go outside once frost danger has fully passed and the soil is warm.

What USDA zone is Wyoming?

Most of Wyoming sits in USDA hardiness zone 4b, with the state spanning roughly 3a-6a from the high mountain basins like Jackson Hole (zone 3a) to the lower southeast plains near Cheyenne (zone 6a). The last spring frost averages late May and the first fall frost mid-September.

Can you grow cantaloupe in Wyoming?

Yes. Wyoming's dominant zone 4b supports cantaloupe — the key is timing. Cantaloupe are frost-tender — a single light frost kills seedlings, so they only go outside once frost danger has fully passed and the soil is warm.

Does the planting date change across Wyoming?

the high mountain basins like Jackson Hole (zone 3a) runs roughly 1-2 weeks behind the state average; the lower southeast plains near Cheyenne (zone 6a) can plant 1-2 weeks earlier.

What else can I plant in Wyoming around the same time?

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.