When to Plant Echinacea in Kenai Peninsula Borough, AK
Echinacea (purple coneflower) is a native prairie perennial valued for its immune-supporting properties and beautiful daisy-like flowers that attract pollinators.
Kenai Peninsula Borough, Alaska is in USDA Zone 5a. The average last spring frost is May 17 and the first fall frost is September 25, giving you a growing season of approximately 131 days.
At an elevation of 1,824 feet, Kenai Peninsula Borough receives approximately 55.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 60°F, so choose short-season varieties of Echinacea to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Echinacea root diseases.
Kenai Peninsula Borough Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.8
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Echinacea Planting Timeline — Kenai Peninsula Borough, AK
Echinacea Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 24 | May 24 – Jun 7 |
| Harvest | September 27 | Sep 27 – Nov 8 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
120–180 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
131 days
Growing Tips for Kenai Peninsula Borough
Start seeds indoors 8-10 weeks before last frost or direct sow in fall for spring germination. Seeds need cold stratification. Deadhead to prolong blooming or leave seed heads for birds.
Companion Planting
Good Companions
Level Up Your Garden
Echinacea in Other Locations
Frequently Asked Questions
When should I plant Echinacea in Kenai Peninsula Borough, AK?
Kenai Peninsula Borough is in Zone 5a with an average last frost of May 17. Plan your Echinacea planting based on this frost date — see the calendar above for exact timing.
What planting zone is Kenai Peninsula Borough, AK?
Kenai Peninsula Borough, Alaska is in USDA Hardiness Zone 5a. The average last spring frost is May 17 and first fall frost is September 25.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Kenai Peninsula Borough gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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