Choose a quick-maturing type and protect young starts from lingering heat. Cut the main head before buds open; some varieties make side shoots.
EdibleCool-season crop
Growing spaceVegetable bedClimate fitUrban core · USDA 9b–10a · Valley suburbs · USDA 9a–9b · Desert outskirts · USDA 8b–9bCrop familyBrassicaceae (mustard)Life cycleAnnual cropPhoenix planting windowStart seed in August–September; transplant September–January, preferably October–December.How to plantStart in trays for fall transplants, or direct sow early in the fall window.Plant spacing18–24 inFrostTolerates light frost once established; cover during a hard freeze.Time to harvestAbout 90–100 days from transplants; 120–130 from seed in the Maricopa calendarSuccessionStagger fall transplants by 2–3 weeks.Special categoriesEDIBLETypical harvestWinter into early spring heads and side shoots.
Before you plant
These conditions determine whether it will thrive.
Cold hardinessCover in a hard freeze below 28°F
Established plants handle light frost, though foliage can burn in the upper 20s. Plants that grew up in warm weather can die below about 22°F, so cover in a hard freeze.
Leaves and wood: damaged below 28°FHeat toleranceNeeds afternoon shade
Likes days around 60 to 70°F. Heat makes heads loose and quick to flower, so finish harvesting by March or early April in Phoenix.
