When to Plant Leeks in Anchorage Municipality, AK
Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.
Anchorage Municipality, Alaska is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 19, giving you a growing season of approximately 127 days.
At an elevation of 2,537 feet, Anchorage Municipality receives approximately 20.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 71°F, so choose short-season varieties of Leeks to ensure they mature before fall.
Anchorage Municipality Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.5
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.
Soil Compatibility in Anchorage Municipality
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (4.9–6.5) is more acidic than Leeks prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Anchorage Municipality is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Leeks.
Organic Matter
Organic matter is excellent (5.2%) — Leeks will thrive.
How to Plant Leeks
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Plant Water Budget
Monthly Watering Guide for Leeks
Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Leeks Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 0.6" | 0" | ❄️ Dormant |
| May | 3.5" | 0.9" | 2.6" | 🚿 Regular watering |
| Jun | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Jul | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| Aug | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Sep | 3.5" | 3.2" | 0.3" | 💧 Light watering |
| Oct | — | 2.4" | 0" | ❄️ Dormant |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Anchorage Municipality). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Leeks Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Leeks Planting Timeline — Anchorage Municipality, AK
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Direct Sow | May 8 | May 8 – May 29 |
| Harvest | August 14 | Aug 14 – Oct 9 |
| Fall Sowing | June 27 | Jun 27 – Jul 11 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Fall Sowing |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 4b
📆 Growing Season
127 days in Anchorage Municipality
Growing Tips for Leeks in Anchorage Municipality
Direct sow Leeks outdoors after May 15 in Anchorage Municipality when soil has warmed and frost danger has passed.
Your 127.0-day growing season in Anchorage Municipality is tight for Leeks (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.
Companion Planting
Good Companions
Avoid Planting Near
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Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Anchorage Municipality, AK?
Anchorage Municipality is in Zone 4b with an average last frost of May 15. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Anchorage Municipality, AK?
Anchorage Municipality, Alaska is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 19.
Plan Your Garden with Confidence
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