Oklahoma planting calendar

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

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

Zucchini planting timetable for Oklahoma

Stage	When in Oklahoma	Anchor
Start seeds indoors	mid-March (March 15)	3 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-June (June 13)	~55 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 zucchini 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 — zucchini stall in cold ground even after the air warms, so don't rush them out.

Zucchini is the fastest-maturing summer squash — soil must reach 18 °C (65 °F) before sowing or transplanting, as cold soil causes slow, weak germination and root rot. One or two plants per family member is usually sufficient; succession-sowing every 3-4 weeks extends harvest but rarely necessary given prolific production. Harvest fruit at 15-20 cm (6-8 inches) every 2-3 days to maintain plant productivity; leaving fruits to overgrow reduces total yield.

Frost-risk note

Don't plant before early April — even a light frost will kill seedlings overnight. 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 — 6-8 hours direct.
Soil temperature for germination: 21-29 °C (70-85 °F).
Spacing: 24-36 inches (60-90 cm) between plants.
Days to harvest: ~55 days from planting out.

Frequently asked questions

When is the best time to plant zucchini in Oklahoma?

In Oklahoma (mostly USDA zone 7b), sow zucchini indoors around mid-March, transplant outdoors mid-April (after the last frost, early April), and harvest from mid-June. Zucchini 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 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 zucchini in Oklahoma?

Yes. Oklahoma's dominant zone 7b supports zucchini — the key is timing. Zucchini 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 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.