Planting Guides

When to Plant Kale in Anchorage: Complete Guide + Best Varieties for Zone 4b

Anchorage, Alaska

USDA Zone 4b

Last Frost: May 20

Last updated: October 30, 2025

Plant kale in Anchorage May 1-15 for summer harvest or July 15-25 for frost-sweetened fall crop in Alaska's unique Zone 4b growing conditions.

DDorothy "Dot" Williams

October 30, 2025

Kale plants growing in Anchorage garden with Alaska mountain backdrop showing Zone 4b conditions — — Image © PlantReference.org 2025

Quick Answer

Plant kale in Anchorage May 1-15 for summer harvest or July 15-25 for fall crop. Alaska's cool temperatures and 20-hour summer daylight create ideal conditions for sweet, tender kale.

TL;DR

Plant kale in Anchorage May 1-15 for summer harvest or July 15-25 for fall crop. Anchorage's Zone 4b climate with 118-day growing season and cool temperatures creates ideal conditions for sweet, tender kale. Brassica oleracea 'Winterbor' and Brassica oleracea 'Red Russian' are top choices for Alaska's short but productive growing window.

Product Recommendations

Alaska Botanical Garden Mixed Kale Seed Collection

https://www.alaskabg.org/shop/mixed-kale-seeds

Specially curated collection of five kale varieties proven to excel in Alaska's Zone 4b climate. Includes Red Russian for quick harvest, Winterbor for cold tolerance, and Lacinato for gourmet flavor. Each packet contains enough seed for 25-30 plants. Selected by Alaska Botanical Garden specifically for short-season, cool-climate success. Seeds are tested for cold-climate germination and adapted to Alaska's unique growing conditions.

Price: $12.99-$14.99

DeWitt N-Sulate NS6X50 6x50ft Floating Row Cover Fabric

https://www.amazon.com/dp/B002M28GIE

Lightweight spun fabric provides 4-6°F frost protection while allowing 85% light transmission for continued growth. Perfect for extending Anchorage's short growing season into October and November. Breathable material prevents overheating during Alaska's cool summers while excluding pests. Easy to install over hoops or directly on plants. Reusable for multiple seasons. Essential tool for maximizing harvest from Alaska's compressed growing window.

Price: $18.99-$24.99

Excalibur 2400 4-Tray Electric Food Dehydrator

https://www.amazon.com/dp/B000TBKZM6

Compact dehydrator ideal for Alaska households wanting to preserve their kale harvest. Four trays provide enough capacity for a family's needs without taking excessive space. Adjustable temperature control works perfectly for kale chips and herb drying. Horizontal airflow ensures even drying in Alaska's variable humidity conditions. Quiet operation and easy cleanup make it practical for year-round use. Durable construction handles frequent use during harvest preservation season.

Price: $65.99-$79.99

Rapitest Digital Soil pH Meter and Moisture Tester

https://www.amazon.com/dp/B000P1NYRU

Essential tool for Anchorage gardeners dealing with naturally acidic soils that limit kale production. Digital display provides accurate pH readings to determine lime requirements for optimal growing conditions. Also measures soil moisture to prevent overwatering in Alaska's wet climate. Durable construction withstands Alaska's challenging outdoor conditions. Quick, easy readings help maintain proper pH 6.0-7.0 range that kale requires for maximum growth and disease resistance.

Price: $15.99-$19.99

Frequently Asked Questions

When should I start kale seeds indoors in Anchorage?

Start kale seeds indoors March 15-30 for spring transplanting, about 6-8 weeks before your planned outdoor planting date of May 1-15. Use a cool location (60-65°F/15-18°C) as kale prefers cooler conditions for germination than many vegetables. Anchorage's naturally cool spring temperatures are actually ideal for hardening off seedlings—just protect them from freezing winds during the transition period.

Can kale survive winter in Anchorage?

Kale cannot survive Anchorage winters outdoors without significant protection due to Zone 4b temperatures regularly dropping below 0°F (-18°C). However, you can extend the harvest season into November using cold frames, row covers, or unheated greenhouses. Brassica oleracea 'Winterbor' offers the best cold tolerance for season extension attempts, surviving down to 10°F (-12°C) with protection.

Why is my spring-planted kale turning yellow in Anchorage?

Yellow leaves on spring kale in Anchorage typically indicate waterlogged soil rather than heat stress (unlikely in Alaska's cool climate). Anchorage's wet springs can saturate soils, preventing proper root function and nutrient uptake. Improve drainage with raised beds or organic matter additions, and avoid overwatering. Cool, wet soil conditions also slow nitrogen uptake, so side-dress with fish emulsion every 3 weeks during active growth.

Which kale variety grows fastest in Alaska's short season?

Brassica oleracea 'Red Russian' is the fastest-maturing variety for Anchorage, ready to harvest in just 50-60 days. This makes it ideal for succession plantings throughout Alaska's short growing season. Its flat, tender leaves are perfect for salads and smoothies, while the purple-veined foliage adds visual interest to Alaska gardens. Plant every 3-4 weeks from May through July for continuous harvest.

How do I know when kale is ready to harvest in Anchorage?

Harvest kale leaves when they reach 6-8 inches long, typically 6-8 weeks after planting in Anchorage conditions. Alaska's cool temperatures keep leaves tender much longer than warmer climates, so you can safely harvest leaves up to 12-14 inches without toughness issues. For fall crops, wait until after the first frost for maximum sweetness—this natural "candy kale" effect only occurs in cool climates like Anchorage.

What's the best way to preserve my Anchorage kale harvest?

Freeze or dehydrate kale for long-term storage. For freezing, blanch leaves 2-3 minutes, cool in ice water, drain thoroughly, and package in freezer bags for winter use. For dehydration, Alaska's dry indoor winter air makes homemade kale chips simple and effective. Store fresh, unharvested kale in the garden under row covers into November for continuous fresh harvests until hard freezes arrive.

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Tagged with

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Written By

Dorothy "Dot" Williams

Dot grew up on a small farm in rural Virginia and has maintained a vegetable garden for decades. After retiring from teaching elementary school, she became a Master Gardener volunteer and spends her time mentoring new gardeners at community garden plots in Richmond. She's especially knowledgeable about heirloom varieties, seed saving, and traditional growing methods passed down from her grandmother. Dot's no-nonsense advice comes from extensive trial and error—she's seen every tomato disease, pest problem, and weather disaster imaginable. Her biggest pet peeve is gardeners who overcomplicate simple tasks. "Plants want to grow," she often says. "Your job is to not get in their way."