When to Plant Nasturtiums in Alaska
Edible flowers that double as pest traps. Plant near vegetables to lure aphids away from your food crops.
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 |
Nasturtiums 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 Nasturtiums in Alaska
Nasturtiums in Alaska's Climate
Nasturtiums add edible beauty to cold-climate gardens from June through frost. Direct sow after last frost — they grow fast in summer warmth. Plant near vegetables as companion and trap plants for aphids. The flowers and leaves have a peppery, watercress-like flavor that brightens salads.
Soil Considerations for Alaska
Varies widely. Interior has permafrost challenges. Raised beds essential for warming soil. Highly acidic soils common. Make sure soil has warmed to at least 55°F before planting nasturtiums outside.
Alaska Climate & Growing Season
Extreme daylight variation. Summer days of 18-24 hours of sunlight accelerate growth. Very short growing season in interior. Nasturtiums cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
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 nasturtiums — transplant timing shifts by several weeks across the state.
Growing Tips
Both flowers and young leaves are edible with a peppery taste. Thrives in poor soil — too much nitrogen means all leaves, no flowers.
Companion Planting
Plant nasturtiums alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026