Missouri planting calendar

When to plant swiss chard in Missouri — sow, transplant & harvest dates

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

Swiss Chard planting timetable for Missouri

Stage	When in Missouri	Anchor
Start seeds indoors	mid-March (March 18)	4 weeks before the last frost (mid-April)
Transplant outside	early April (April 8)	7 days before the last frost (mid-April)
First harvest (estimate)	early June (June 2)	~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 Missouri's climate shifts the swiss chard dates

Missouri's last spring frost averages mid-April and first fall frost mid-October, which sets the whole planting clock. Missouri has a humid continental climate with hot summers and a southeastern Bootheel that gardens nearly a zone warmer than the north. Sow early — swiss chard bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

Swiss chard is notably more versatile than spinach — it tolerates both light frost (surviving to about -4 °C) and summer heat up to 32 °C, making it a near-year-round crop in Zones 7–10. Direct-sow or transplant 1 week before the last spring frost; chard seed is actually a multi-germ cluster, so thin to final spacing after germination to prevent overcrowding. Unlike spinach, it does not readily bolt in summer, so a single sowing can be harvested by cutting outer leaves repeatedly for 3–4 months.

Frost-risk note

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

Regional variation within Missouri

the northern counties near Iowa (zone 5b) runs roughly 1-2 weeks behind the state average; the Bootheel in the southeast (zone 7a) can plant 1-2 weeks earlier.

Kansas City — USDA zone 6b
St. Louis — USDA zone 7a
Springfield — USDA zone 7a
Columbia — USDA zone 6b

What else to plant in Missouri around then

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

Quick-grow guide

Sun: Full sun to partial shade.
Soil temperature for germination: 10-29 °C (50-85 °F).
Spacing: 9-12 inches (23-30 cm) between plants.
Days to harvest: ~55 days from planting out.

Frequently asked questions

When is the best time to plant swiss chard in Missouri?

In Missouri (mostly USDA zone 6b), sow swiss chard indoors around mid-March, transplant outdoors early April (before the last frost, mid-April), and harvest from early June. Swiss Chard 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 Missouri?

Most of Missouri sits in USDA hardiness zone 6b, with the state spanning roughly 5b-7a from the northern counties near Iowa (zone 5b) to the Bootheel in the southeast (zone 7a). The last spring frost averages mid-April and the first fall frost mid-October.

Can you grow swiss chard in Missouri?

Yes. Missouri's dominant zone 6b supports swiss chard — the key is timing. Swiss Chard 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 Missouri?

the northern counties near Iowa (zone 5b) runs roughly 1-2 weeks behind the state average; the Bootheel in the southeast (zone 7a) can plant 1-2 weeks earlier.

What else can I plant in Missouri 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.