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Illinois planting calendar

When to plant spinach in Illinois — sow, transplant & harvest dates

Illinois is mostly USDA zone 6a (range 5a-7a). Dates below are derived from spinach's frost tolerance and Illinois's frost window — not generic national averages.

Spinach planting timetable for Illinois

StageWhen in IllinoisAnchor
Direct-sow outsidelate March (March 21)35 days before the last frost (late April)
First harvest (estimate)early May (May 5)~45 days from direct sow

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 Illinois's climate shifts the spinach dates

Illinois's last spring frost averages late April and first fall frost mid-October, which sets the whole planting clock. Illinois has a productive continental Midwest climate. The south of the state runs nearly two half-zones warmer than the Chicago area. Sow early — spinach bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

Spinach is direct-sown only — it does not transplant well and runs to seed quickly under any stress. Sow as soon as soil can be worked, 4–6 weeks before the last spring frost; it germinates in soil as cold as 4 °C and seedlings survive light freezes to -6 °C. Bolt risk rises sharply once daytime temperatures consistently exceed 24 °C or day length passes 14 hours, so succession-sow every 2 weeks and switch to heat-tolerant varieties in late spring. In Zones 7–10, a second sowing in late summer or early fall produces the best crop of the year.

Frost-risk note

Don't plant before late April — a hard freeze can still set young plants back. In the northern counties near the Wisconsin line (zone 5a) the safe date runs a week or two later.

Regional variation within Illinois

the northern counties near the Wisconsin line (zone 5a) runs roughly 1-2 weeks behind the state average; the far south near Cairo and Carbondale (zone 7a) can plant 1-2 weeks earlier.

What else to plant in Illinois around then

The same early window suits peas, lettuce, spinach, and onion sets.

Quick-grow guide

Frequently asked questions

When is the best time to plant spinach in Illinois?

In Illinois (mostly USDA zone 6a), direct-sow spinach late March (before the last frost, late April), and harvest from early May. Spinach 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 Illinois?

Most of Illinois sits in USDA hardiness zone 6a, with the state spanning roughly 5a-7a from the northern counties near the Wisconsin line (zone 5a) to the far south near Cairo and Carbondale (zone 7a). The last spring frost averages late April and the first fall frost mid-October.

Can you grow spinach in Illinois?

Yes. Illinois's dominant zone 6a supports spinach — the key is timing. Spinach 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 Illinois?

the northern counties near the Wisconsin line (zone 5a) runs roughly 1-2 weeks behind the state average; the far south near Cairo and Carbondale (zone 7a) can plant 1-2 weeks earlier.

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

The same early window suits peas, lettuce, spinach, and onion sets.

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.

Keep going

Same crop, nearby states (Midwest)

Other crops for Illinois