When to plant thyme in Baltimore, Maryland
March 24 – April 7
Transplant outdoors · typical Baltimore yearClimate basis: NOAA station Md Sci Ctr Baltimore, MD (USW00093784), 1 mi (2 km) from downtown Baltimore (ZCTA 21202 centroid), elevation 20 ft, on the 1991–2020 climate normals. Transplant thyme outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (March 24). One year in ten still freezes after April 4.
The Baltimore year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to Apr 4
Every method, with its sources
Transplant outdoors
Mar 24 – Apr 7Oklahoma State Table 1: plant thyme after the last spring frost (seed or cuttings; most gardeners set out plants). Point rule given a 14-day span. Anchored to the median last spring freeze (Mar 24). Oklahoma State University Extension
Start seeds indoors
Not calculatedThe cited guide gives no indoor seed-starting lead time for thyme, so no window is calculated.
Direct-sow outdoors
Not calculatedThe cited extension guides do not time direct sowing for this crop.
Fall planting
Not calculatedNo source-backed fall planting rule exists for this crop in the registry, so no fall window is calculated.
Variety assumption: A hardy perennial once established; harvest lightly the first season.
These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.
Crop rule sources (1)
- Oklahoma State University Extension: Culinary Herbs for Oklahoma Gardens: Culture, Use and Preservation (accessed 2026-07-24)Table 1 planting times relative to last spring frost for common herbs.