Planting Guides

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

Anchorage, Alaska

USDA Zone 4b

Last Frost: May 20

Last updated: October 30, 2025

Plant cucumbers in Anchorage after May 20 using transplants or direct sow June 1-15. Zone 4b's 118-day growing season requires fast-maturing varieties and season extension techniques.

TTom Erikson

October 30, 2025

Cucumber plants growing in Anchorage garden with protective row covers for Zone 4b climate — — Image © PlantReference.org 2026

Quick Answer

Start cucumber transplants indoors April 25, plant outdoors after May 20. Choose varieties maturing in 50-65 days for Zone 4b success.

TL;DR

Plant cucumbers in Anchorage after May 20 using transplants started indoors April 25. Direct sowing works June 1-15 when soil reaches 60°F. Choose fast-maturing varieties like Cucumis sativus 'Boston Pickling' (55 days) and use black plastic mulch and row covers for maximum heat accumulation in Zone 4b's 118-day growing season.

Frequently Asked Questions

When is the latest I can plant cucumbers in Anchorage?

July 10 is the absolute latest for 65-day varieties, but I recommend finishing all plantings by June 15. Anchorage's September 15 first frost date means late plantings rarely mature fully. Early frosts can occur, making June plantings much safer.

Can I direct sow cucumber seeds in Anchorage?

Yes, but only from June 1-15 when soil reaches 60°F consistently. Direct sowing works best for Cucumis sativus 'Northern Pickling' and other fast-maturing varieties. Transplants remain the safer option for Zone 4b's short season.

What's the best way to extend the season for cucumbers in Anchorage?

Black plastic mulch and floating row covers are essential. I also use cold frames or small hoop tunnels for extra protection. Plant against south-facing walls or buildings to capture reflected heat. Container growing allows moving plants to protected areas during cool spells.

Do cucumber varieties bred for northern climates really make a difference?

Absolutely. Cucumis sativus 'Northern Pickling' and similar varieties developed for short seasons mature 10-15 days faster than standard varieties. This timing difference often determines success or failure in Zone 4b conditions.

How do I know when soil is warm enough for cucumber planting?

Use a soil thermometer 2-3 inches (5-7 cm) deep. Wait for consistent readings above 55°F for transplants, 60°F for direct seeding. In Anchorage, this typically occurs May 20-25 for transplants and June 1-10 for direct sowing.

Can I grow cucumbers in containers in Anchorage?

Container growing works excellently for Anchorage conditions. Use 5-gallon minimum containers with drainage holes. Black containers absorb heat, warming root zones faster. Choose compact varieties like Cucumis sativus 'Bush Champion' for best results.

What should I do if early frost threatens my cucumber plants?

Cover plants with blankets, row covers, or plastic sheeting. Harvest all fruits regardless of size—small cucumbers make excellent pickles. Container plants can be moved indoors temporarily. Even one night's protection often provides several extra harvesting days.

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Tagged with

#cucumber planting #Anchorage gardening #Zone 4b vegetables #Alaska gardening #short season growing #cucumber varieties #transplant timing #season extension #frost protection #northern gardening

Written By

Tom Erikson

Tom is a lifelong Alaskan who gardens in Anchorage, where the growing season is short but intense. He works for the state cooperative extension service and has spent years figuring out what works in a climate where the ground freezes deep, the growing season starts in late May, and you get 19 hours of daylight in June. Tom grows cold-hardy vegetables, maintains a collection of boreal-adapted perennials, and experiments with season extension using cold frames and row covers. He writes about the realities of northern gardening—the unique advantages (those long summer days produce remarkable growth) and the genuine limitations. Tom's tone is calm and practical, with the quiet humor of someone who's gardened through Alaskan winters for decades.