When to plant parsley in Madison, Wisconsin
April 10 – April 24
Transplant outdoors · typical Madison yearClimate basis: NOAA station Uw Arboretum - Madison, WI (USC00470273), 4 mi (6 km) from downtown Madison (ZCTA 53703 centroid), elevation 870 ft, on the 1991–2020 climate normals. Transplant parsley outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (May 1). One year in ten still freezes after May 17.
The Madison year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to May 17
Every method, with its sources
Start seeds indoors
Jan 30 – Feb 13Wisconsin: start seeds indoors 8–10 weeks before the last frost (UNH: 9–10 weeks from seed to transplant). Parsley germinates slowly. Anchored to the median last spring freeze (May 1). University of Wisconsin–Madison Division of Extension (Wisconsin Horticulture) · University of New Hampshire Extension
Transplant outdoors
Apr 10 – Apr 24UNH: set out 2–3 weeks before the last frost; Oklahoma State plants 3–4 weeks before. The later UNH range is used. Anchored to the median last spring freeze (May 1). University of New Hampshire Extension · Oklahoma State University Extension
Direct-sow outdoors
Apr 3 – Apr 17Oklahoma State Table 1: plant parsley three to four weeks before the last spring frost. Anchored to the median last spring freeze (May 1). Oklahoma State University Extension
Variety assumption: Leaf harvest begins about 70–90 days from seed.
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 (3)
- University of Wisconsin–Madison Division of Extension (Wisconsin Horticulture): Parsley, Petroselinum crispum (accessed 2026-07-24)"Start seeds indoors 8-10 weeks before last frost."
- University of New Hampshire Extension: Growing Vegetables: When to Plant Your Vegetable Garden [fact sheet] (accessed 2026-07-24)Per-crop 'time from seed to transplant' and 'safe to set out in garden' relative to last frost.
- 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.