Oklahoma planting calendar

When to plant rosemary in Oklahoma — sow, transplant & harvest dates

Oklahoma is mostly USDA zone 7b (range 6b-8a). Dates below are derived from rosemary's frost tolerance and Oklahoma's frost window — not generic national averages.

Rosemary planting timetable for Oklahoma

Stage	When in Oklahoma	Anchor
Start seeds indoors	late January (January 25)	10 weeks before the last frost (early April)
Transplant outside	mid-April (April 19)	14 days after the last frost (early April)
First harvest (estimate)	mid-July (July 18)	~90 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 Oklahoma's climate shifts the rosemary dates

Oklahoma's last spring frost averages early April and first fall frost late October, which sets the whole planting clock. Oklahoma has a long, hot, often windy season. Summer heat and drought stress are as limiting as the winter low across most of the state. Wait for warm soil — rosemary stall in cold ground even after the air warms, so don't rush them out.

Start seeds indoors 10–12 weeks before the last frost; germination is slow and erratic (14–21 days at 18–21 °C / 65–70 °F) with low viability, so propagation by stem cuttings is preferred by most Extension services. Transplant outdoors after the last frost once soil has warmed — rosemary is perennial only in USDA zones 7–10 (established plants survive to about −12 °C / 10 °F); in zones 6 and colder treat as a tender annual or overwinter potted plants indoors before the first autumn frost. Tip harvests of stem ends begin around 80–100 days from transplant.

Frost-risk note

Don't plant before early April — a hard freeze can still set young plants back. In the Panhandle High Plains (zone 6b) the safe date runs a week or two later.

Regional variation within Oklahoma

the Panhandle High Plains (zone 6b) runs roughly 1-2 weeks behind the state average; the south-central and southeast lowlands (zone 8a) can plant 1-2 weeks earlier.

Oklahoma City — USDA zone 7b
Tulsa — USDA zone 7b
Norman — USDA zone 7b
Lawton — USDA zone 8a

What else to plant in Oklahoma 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: 18–21 °C (65–70 °F).
Spacing: 18–36 inches (45–90 cm) between plants.
Days to harvest: ~90 days from planting out.

Frequently asked questions

When is the best time to plant rosemary in Oklahoma?

In Oklahoma (mostly USDA zone 7b), sow rosemary indoors around late January, transplant outdoors mid-April (after the last frost, early April), and harvest from mid-July. Rosemary are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

What USDA zone is Oklahoma?

Most of Oklahoma sits in USDA hardiness zone 7b, with the state spanning roughly 6b-8a from the Panhandle High Plains (zone 6b) to the south-central and southeast lowlands (zone 8a). The last spring frost averages early April and the first fall frost late October.

Can you grow rosemary in Oklahoma?

Yes. Oklahoma's dominant zone 7b supports rosemary — the key is timing. Rosemary are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

Does the planting date change across Oklahoma?

the Panhandle High Plains (zone 6b) runs roughly 1-2 weeks behind the state average; the south-central and southeast lowlands (zone 8a) can plant 1-2 weeks earlier.

What else can I plant in Oklahoma 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.