Maryland planting calendar

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

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

Thyme planting timetable for Maryland

Stage	When in Maryland	Anchor
Start seeds indoors	mid-February (February 18)	8 weeks before the last frost (mid-April)
Transplant outside	mid-April (April 15)	0 days after the last frost (mid-April)
First harvest (estimate)	early July (July 9)	~85 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 thyme 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. Wait for warm soil — thyme stall in cold ground even after the air warms, so don't rush them out.

Start seeds indoors 8–10 weeks before the last spring frost; germination takes 14–21 days at 18–21 °C (65–70 °F). Harden off transplants and set out around the date of last frost — thyme is perennial in USDA zones 5–9 (RHS H5) but resents waterlogged soil far more than cold. In the first growing season allow only light harvesting so the plant can establish; full harvests from the second year onward, cutting stems back to 4–5 cm above woody growth.

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

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 18–21 °C (65–70 °F).
Spacing: 6–8 inches (15–20 cm) between plants.
Days to harvest: ~85 days from planting out.

Frequently asked questions

When is the best time to plant thyme in Maryland?

In Maryland (mostly USDA zone 7b), sow thyme indoors around mid-February, transplant outdoors mid-April (after the last frost, mid-April), and harvest from early July. Thyme 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 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 thyme in Maryland?

Yes. Maryland's dominant zone 7b supports thyme — the key is timing. Thyme 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 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?

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.