Growing romanesco in zone 9b

(Zone 9b = an average winter low of 25°F to 30°F.)

In USDA zone 9b, the typical last spring frost is February 1 and the first fall frost is December 9. Here is when to plant romanesco against those dates.

Start seeds indoorsDecember 21 to January 4

Transplant outdoorsFebruary 1

Expected harvestApril 17 to May 12About 75 to 100 days from transplanting.

These are zone 9b averages

Computed from 2,081 ZIP codes in zone 9b. 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.