When to Plant Radishes in Alaska
The fastest vegetable in the garden — some varieties are ready in just 25 days. Perfect for impatient gardeners and kids.
The Short Answer
Alaska Frost Dates
Your planting dates depend on which part of Alaska you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Interior Alaska | 1a, 2a, 2b | May 15 - Jun 1 | Aug 20 - Sep 10 |
| Southcentral Alaska | 3b, 4a, 4b | May 1 - May 20 | Sep 10 - Sep 25 |
| Southeast Alaska | 5a, 5b, 6a | Apr 15 - May 5 | Sep 25 - Oct 15 |
Radishes Planting Schedule for Alaska
Interior Alaska (Zones 1a, 2a, 2b)
Average last frost: May 15 - Jun 1 · Average first frost: Aug 20 - Sep 10
Southcentral Alaska (Zones 3b, 4a, 4b)
Average last frost: May 1 - May 20 · Average first frost: Sep 10 - Sep 25
Southeast Alaska (Zones 5a, 5b, 6a)
Average last frost: Apr 15 - May 5 · Average first frost: Sep 25 - Oct 15
Growing Radishes in Alaska
Radishes in Alaska's Climate
Radishes are perfect for cold-climate gardens — they're the fastest crop from seed to harvest (as few as 22 days) and tolerate frost. Direct sow as soon as soil thaws. Your cool, long spring means radishes grow for weeks without the bolting pressure that ends the season rapidly in warm zones. Fall radishes from an August sowing are equally productive.
Soil Considerations for Alaska
Varies widely. Interior has permafrost challenges. Raised beds essential for warming soil. Highly acidic soils common. Loose, well-drained soil is especially important for radishes since the edible portion grows underground. If your soil is heavy clay, consider raised beds.
Alaska Climate & Growing Season
Extreme daylight variation. Summer days of 18-24 hours of sunlight accelerate growth. Very short growing season in interior. Radishes can handle frost well, which is an advantage in Alaska's climate. You can push planting dates earlier in spring and extend into fall.
Growing season length varies across Alaska: Interior Alaska (1a, 2a, 2b) has a last frost around May 15 - Jun 1, while Southeast Alaska (5a, 5b, 6a) sees frost end around Apr 15 - May 5. This difference matters for radishes — but radishes handle frost well, so the timing difference is less critical.
Growing Tips
Don't let them stay in the ground too long — they get pithy and hot. Succession plant every 2 weeks for continuous harvest.
Companion Planting
Plant radishes alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026