When to Plant Spinach in Oklahoma
Published: April 24, 2026
Oklahoma gardeners in Zone 7a have a 35-week growing season for spinach (March 15 to November 15). Oklahoma's spring and fall windows both work well for spinach — some gardeners plant both successions for a long harvest. This guide gives exact dates for Oklahoma based on your local frost calendar.
Spinach Planting Dates for Oklahoma
| Start seeds indoors | Year-round |
| Last frost (average) | March 15 |
| Direct sow outdoors | February 8–18 |
| Expect first harvest | March 20 – March 30 |
| Fall crop start | October 4–14 |
| Fall harvest | November 13 |
| First fall frost (average) | November 15 |
⚠ One of the earliest spring vegetables — sow 4–6 weeks before last frost. Bolts in heat above 75°F. Plant again in late summer for a fall harvest.
Growing Spinach in Oklahoma's Climate
Oklahoma's moderate Zone 7a climate is well-suited to spinach with minimal special accommodation. The standard transplant calendar works as written, and harvest windows line up with what seed packets recommend without adjustment.
Succession planting extends your spinach harvest significantly in Oklahoma. A second planting 3 to 4 weeks after the first gives you a backup in case of pest pressure and extends the total harvest window into early fall.
Common spinach pests to watch for in Oklahoma include Leaf Miner and Aphid. The first line of defense is companion planting: Pea and Strawberry planted nearby discourage several of these pests by confusing host-plant identification or repelling adults before they can lay eggs. Weekly garden walks in the early morning catch problems when they're still manageable.
Spinach Garden Calendar for Oklahoma
| Month | Task | Notes |
|---|---|---|
| January | — | Dormant season |
| February | Direct sow seeds | Sow seeds 1/4–1/2 inch deep, 6 inches apart |
| March | First harvest window opens | Spinach begins producing 40–50 days after transplant |
| April | — | Dormant season |
| May ← | Watch for bolting | Harvest promptly; spring heat arrives quickly |
| June | — | Dormant season |
| July | — | Dormant season |
| August | — | Dormant season |
| September | — | Dormant season |
| October | Fall crop planting | Transplant or direct sow for fall harvest before frost |
| November | First frost approaches | Harvest remaining spinach; cover plants on frost nights |
| December | — | Dormant season |
Spinach Growing Tips for Oklahoma Gardeners
- •Direct sow in very cold soil — spinach germinates at 35°F, earlier than almost any other crop.
- •Succession plant every 10 days until 2 weeks before heat sets in for continuous spring harvests.
- •Oklahoma's moderate climate supports succession planting — sow new transplants or seeds every 3 weeks during spring to extend the harvest window into fall.
- •Switch to bolt-resistant varieties like Malabar or New Zealand spinach for summer heat (though technically different species).
Companion Planting for Spinach in Oklahoma
In Oklahoma's moderate climate, planting spinach with Pea and Strawberry helps deter pests and improve soil. Avoid planting near Fennel, which inhibit spinach growth through root chemistry or shared pest pressure. See the full spinach companion planting guide for the complete list.
Spinach Planting Dates by City in Oklahoma
Top cities in Oklahoma — select for city-level frost dates and planting calendars.
Frequently Asked Questions
When should I plant spinach in Oklahoma?
In Oklahoma (Zone 7a), start spinach seeds indoors around Year-round and transplant outdoors around null — 0 weeks after the state's average last frost of March 15.
What is the last frost date in Oklahoma?
Oklahoma's average last frost date is March 15 in the state's most common Zone 7a. Frost dates vary by city — higher elevations and northern counties run 1 to 3 weeks later than the state average. See the city list below for city-level frost dates.
Can I grow spinach year-round in Oklahoma?
spinach is a cool-season crop in Oklahoma, with spring and fall windows. Summer heat bolts the plants before they can produce a harvestable crop. Succession planting every 2–3 weeks stretches the harvest window.
What spinach varieties grow best in Oklahoma?
For Oklahoma's Zone 7a, consult a local nursery or extension office for spinach variety recommendations.
When do I start spinach seeds indoors in Oklahoma?
Spinach does not need indoor starting in Oklahoma — direct sow around February 8–18 once soil reaches 35°F. Indoor starting is not recommended for this crop because spinach transplants poorly.