Planting Guides
When to Plant Kale in Phoenix: Complete Guide + Best Varieties for Zone 9b
Phoenix, Arizona
USDA Zone 9b
Last Frost: Feb 15
Last updated: October 30, 2025
Plant kale in Phoenix October through January for winter harvest. Zone 9b's desert climate requires cool-season timing to avoid summer bolting.
— Image © PlantReference.org 2026
Quick Answer
Plant kale in Phoenix October through January for winter harvest. Summer temperatures above 85°F cause immediate bolting.
TL;DR
Phoenix kale thrives October through March in Zone 9b desert conditions. Plant in mid-October for December harvest or late December for spring harvest. Choose heat-tolerant varieties like Brassica oleracea 'Red Russian' and Brassica oleracea 'Lacinato'. Avoid summer planting completely—temperatures above 85°F cause immediate bolting and bitter leaves.
Frequently Asked Questions
When should I plant kale in Phoenix for the best harvest?
Plant kale in Phoenix between October 15-30 for winter harvest or December 1 - January 15 for spring harvest. Fall planting produces the best quality kale because plants mature in cool weather. Avoid summer planting completely—temperatures above 85°F cause immediate bolting and bitter leaves. The sweet spot is October planting for December through March harvest when Phoenix weather is perfect for kale.
Can kale survive Phoenix summer heat?
No, kale cannot survive Phoenix summer heat. Temperatures above 85°F cause bolting (flowering) and bitter leaves, while temperatures above 100°F kill plants within hours. Phoenix summers regularly exceed 110°F, making summer kale growing impossible. Treat kale as a cool-season crop only, growing from October through April. Plant in fall for winter harvest, then start tomatoes and peppers in the same space for summer.
Which kale varieties work best in Phoenix desert conditions?
Brassica oleracea 'Red Russian' and Brassica oleracea 'Lacinato' perform best in Phoenix. Red Russian handles temperature fluctuations better than curly varieties and matures quickly (50 days) for multiple plantings. Lacinato's thick leaves resist desert sun and wind damage better than delicate varieties. For containers, choose compact Brassica oleracea 'Vates' which grows only 12-16 inches tall and uses water efficiently.
How do I protect kale from Phoenix's intense sun and heat?
Plant kale in locations with morning sun and afternoon shade, especially in spring. Use shade cloth (30-50% shade) when temperatures climb above 80°F in March and April. Apply 2-3 inches of organic mulch to keep roots cool and retain moisture. Water deeply twice weekly during establishment, then weekly once mature. Choose thick-leaved varieties like Lacinato that resist sun damage better than thin-leaved types.
What's the latest I can plant kale in Phoenix?
February 1st is the absolute latest for Phoenix kale planting. Only fast-maturing varieties like Brassica oleracea 'Red Russian' (50 days) have time to mature before May heat arrives. Even late February plantings need afternoon shade protection and careful monitoring. For reliable harvests, plant by January 15th. December and January plantings provide the best spring harvest before summer heat makes growing impossible.
How often should I water kale in Phoenix's dry climate?
Water established kale plants once weekly with deep soaking during Phoenix's cool season. Newly planted seeds and transplants need twice weekly watering until established. Apply 1 inch of water per week through drip irrigation or soaker hoses to minimize evaporation. Water early morning to reduce loss to evaporation. Phoenix's low humidity means kale needs consistent moisture to prevent leaf toughness and bitter flavors.
Can I grow kale year-round in Phoenix?
No, Phoenix cannot support year-round kale growing due to extreme summer heat. Growing season runs October through April only—approximately 7 months. Summer temperatures exceeding 110°F kill kale plants immediately. Plan two plantings: October for winter harvest and December/January for spring harvest. Use summer months to grow heat-loving crops like tomatoes, peppers, and eggplant, then return to cool-season crops in fall.
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Alejandro Vega
Alejandro is a landscape designer in Phoenix who focuses on low-water, desert-adapted plantings. He grew up in Tucson surrounded by Sonoran Desert plants and got frustrated watching neighbors install water-hungry lawns in a city that gets eight inches of rain a year. After earning his landscape architecture degree, he started designing residential gardens using native and desert-adapted species. Alejandro's approach is practical—he works with the climate rather than against it, using microclimates, shade structures, and efficient irrigation to create gardens that look good without draining the aquifer. He's a regular speaker at local xeriscaping workshops.
