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What Can Grow in Zone 1a?

Growing Zone Zone 1a
Frost-Free Days 14
Last Frost early July
First Frost mid-July

Extreme subarctic cold. Only the hardiest perennials and short-season cool crops are viable in the brief summer window.

Find your exact zone:

📅 Planting Calendar for Zone 1a

When to start seeds indoors and transplant outdoors, based on your average frost dates. Actual timing shifts year to year — use these as a starting point, not a fixed schedule.

Plant Start Indoors Transplant Out Direct Sow Harvest
🥬 Cabbage May 20 Jul 1 — Sep 9 – Oct 29
🌱 Microgreens — — Jul 1 Jul 8 – Jul 22

Dates are averages based on Zone 1a frost dates (last frost: early July, first frost: mid-July). Frost can come earlier or later than usual — always check your 10-day forecast before transplanting.

🥦 Vegetables

⚠️ Worth Trying (Marginal)

These plants are outside the ideal zone range but possible with the right approach.

🗺️ USDA Plant Hardiness Zones

Zone 1 is shown in this colour on the map below
2023 USDA Plant Hardiness Zone Map — zones 1 to 13

2023 USDA Plant Hardiness Zone Map — public domain. USDA Agricultural Research Service

1 2 3 4 5 6 7 8 9 10 11 12 13

USDA zones run 1a–13b (26 half-zones). Each full zone above covers both the a and b half-zones. Browse all US zones →

Browse Related Zones

Zone 1a Zone 1b Zone 2a Zone 2b Zone 3a Zone 3b Zone 4a Zone 4b Zone 5a

Frequently Asked Questions

Extreme subarctic cold. Only the hardiest perennials and short-season cool crops are viable in the brief summer window. Vegetables like Cabbage, Microgreens all grow well here.
The growing season is short — roughly 14 days. Focus on fast-maturing varieties and start seeds indoors as early as possible.
Top vegetables for Zone 1a: Cabbage, Microgreens.
Most common herbs grow well in Zone 1a.