Maryland planting calendar

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

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

Swiss Chard planting timetable for Maryland

Stage	When in Maryland	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 Maryland's climate shifts the swiss chard dates

Maryland's last spring frost averages mid-April and first fall frost late October, which sets the whole planting clock. Maryland spans cool western mountains to a mild Chesapeake tidewater, giving a long, varied mid-Atlantic season. 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 western Appalachian panhandle near Oakland (zone 6a) the safe date runs a week or two later.

Regional variation within Maryland

the western Appalachian panhandle near Oakland (zone 6a) runs roughly 1-2 weeks behind the state average; the Chesapeake and Atlantic shoreline (zone 8a) can plant 1-2 weeks earlier.

Baltimore — USDA zone 8a
Annapolis — USDA zone 7b
Rockville — USDA zone 7b
Frederick — USDA zone 7a
Ocean City — USDA zone 8a

What else to plant in Maryland 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 Maryland?

In Maryland (mostly USDA zone 7b), 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 Maryland?

Most of Maryland sits in USDA hardiness zone 7b, with the state spanning roughly 6a-8a from the western Appalachian panhandle near Oakland (zone 6a) to the Chesapeake and Atlantic shoreline (zone 8a). The last spring frost averages mid-April and the first fall frost late October.

Can you grow swiss chard in Maryland?

Yes. Maryland's dominant zone 7b 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 Maryland?

the western Appalachian panhandle near Oakland (zone 6a) runs roughly 1-2 weeks behind the state average; the Chesapeake and Atlantic shoreline (zone 8a) can plant 1-2 weeks earlier.

What else can I plant in Maryland 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.