Wyoming planting calendar

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

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

Oregano planting timetable for Wyoming

Stage	When in Wyoming	Anchor
Start seeds indoors	mid-April (April 13)	6 weeks before the last frost (late May)
Transplant outside	late May (May 25)	0 days after the last frost (late May)
First harvest (estimate)	mid-August (August 13)	~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 oregano 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 — oregano stall in cold ground even after the air warms, so don't rush them out.

Oregano is a hardy perennial in zones 5-10 and is easiest to start from seed indoors 6-8 weeks before the last spring frost, or from divisions or cuttings; seeds are tiny and slow to produce harvestable growth. Transplant outdoors around the last frost date once soil has warmed to at least 13 °C — established plants tolerate light frost. In zones 4 and colder, treat as an annual or overwinter divisions in a cold frame; in zones 9-11 it stays evergreen but may die back in intense summer heat without afternoon shade.

Frost-risk note

Don't plant before late May — a hard freeze can still set young plants back. 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+ hours direct.
Soil temperature for germination: 13-21 °C (55-70 °F).
Spacing: 8-12 inches (20-30 cm) between plants.
Days to harvest: ~80 days from planting out.

Frequently asked questions

When is the best time to plant oregano in Wyoming?

In Wyoming (mostly USDA zone 4b), sow oregano indoors around mid-April, transplant outdoors late May (after the last frost, late May), and harvest from mid-August. Oregano are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

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 oregano in Wyoming?

Yes. Wyoming's dominant zone 4b supports oregano — the key is timing. Oregano are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

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.