Growing romanesco in zone 3a

(Zone 3a = an average winter low of -40°F to -35°F.)

In USDA zone 3a, the typical last spring frost is May 29 and the first fall frost is September 5. Here is when to plant romanesco against those dates.

Start seeds indoorsApril 17 to May 1

Transplant outdoorsMay 29

Expected harvestAugust 12 to September 6About 75 to 100 days from transplanting.

These are zone 3a averages

Computed from 17 ZIP codes in zone 3a. Your town's frost dates vary; enter your ZIP for dates built on your nearest weather station.

Get my exact dates

USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service / Oregon State University PRISM Group. NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020. Planting windows for romanesco from University of Wisconsin-Madison Division of Extension. Zone dates are medians; local conditions vary.