What Can Grow in Zone 1a
Extreme subarctic zone with very short frost-free seasons and severe winters. Only the hardiest plants survive.
Zone 1a has average winter lows of -60°F to -55°F (-51°C to -48°C). You can grow kale, cabbage, radishes, and many more plants. The frost-free growing season lasts about 50 days.
Start seeds indoors 8-10 weeks before last frost. Use cold frames and row covers to extend season. Focus on cold-tolerant varieties bred for short seasons.
Frequently Asked Questions
USDA Zone 1a has average annual minimum temperatures of -60°F to -55°F (-51°C to -48°C). This temperature range determines which perennial plants can survive winter outdoors.
The average last frost date in Zone 1a is around June 15, and the first fall frost typically arrives around August 15. This gives a frost-free growing season of approximately 50 days.
Zone 1a is well-suited for kale, cabbage, radishes, turnips, lettuce, spinach. Start seeds indoors 8-10 weeks before last frost. Use cold frames and row covers to extend season. Focus on cold-tolerant varieties bred for short seasons.
Fruits that thrive in Zone 1a include cloudberries, crowberries, lingonberries, arctic raspberries. Always check that specific cultivars are hardy to your zone before planting perennial fruit trees and shrubs.