When to plant celosia in Madison, Wisconsin
May 1 – May 15
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 celosia 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
Apr 3 – Apr 17University of Maryland's celosia production guide states seed is sown 4 weeks before the last frost date, which is the only frost-anchored figure found (Minnesota's 10-weeks guidance is anchored to the outdoor planting date, not to frost, so it cannot be used), giving a two-week sowing span opening 4 weeks before the median last freeze. Anchored to the median last spring freeze (May 1). University of Maryland Extension · University of Minnesota Extension · University of Illinois Extension
Transplant outdoors
May 1 – May 15University of Maryland says to sow or transplant celosia in the field after the danger of frost has passed, so the window opens at the median last freeze; note Maryland's stricter companion rule of night temperatures consistently above 65 to 70 degrees F is not frost-anchored and cannot be expressed here, so the window's opening day is optimistic in cool-summer areas. Anchored to the median last spring freeze (May 1). University of Maryland Extension · University of Minnesota Extension · University of Illinois Extension
Direct-sow outdoors
May 1 – May 15The same University of Maryland sentence covers direct sowing — sow or transplant celosia in the field after the danger of frost has passed — so direct sowing opens at the median last freeze, with Illinois independently classing celosia a tender annual. Anchored to the median last spring freeze (May 1). University of Maryland Extension · University of Minnesota Extension · University of Illinois Extension
Variety assumption: Assumes Celosia argentea in its crested (cockscomb) and plumed forms; Maryland warns that exposure below 60 degrees F stunts plants and triggers premature flowering, so the frost-anchored window opens earlier than the temperature at which celosia actually thrives.
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 Maryland Extension: Production of Celosia as a Cut Flower (accessed 2026-07-25)"Sow Celosia 4 weeks before the last frost date."
- University of Minnesota Extension: Celosia (accessed 2026-07-25)"Celosia seeds can be started indoors about 10 weeks prior to the anticipated outdoor planting date."
- University of Illinois Extension: Celosia — Flowers (accessed 2026-07-25)"Tender Annual"