When to Plant Broccoli in Anchorage Municipality, AK
Anchorage Municipality, Alaska gardeners: here's your May plan
A quick May briefing for Anchorage Municipality, Alaska gardeners — what's urgent, what's next, and what can wait.
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Time to transplant broccoli
Your last frost (May 15) has passed. These warm-season crops can handle outdoor soil now.
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Put broccoli seeds straight in the ground
Your soil is 46°F — warm enough for these to germinate without babying.
Coming up in June — start thinking about
- Starting indoors: broccoli
Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.
Anchorage Municipality, Alaska is in USDA Zone 5a. 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 Broccoli 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 Broccoli's growing requirements.
Soil pH
Your soil pH (4.9–6.5) is more acidic than Broccoli prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Anchorage Municipality is excellent for Broccoli — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Broccoli.
Organic Matter
Organic matter is excellent (5.2%) — Broccoli will thrive.
How to Plant Broccoli
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Broccoli
Sow every 6.9 weeks. Last sowing by Jun 21 to harvest before frost.
For a dedicated fall crop, sow by Jul 11.
Plant Water Budget
Monthly Watering Guide for Broccoli
Broccoli needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Broccoli Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 0.6" | 0" | ❄️ Dormant |
| May | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jun | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jul | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Aug | 4.3" | 3.3" | 1" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 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.
Broccoli 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.
Broccoli Planting Timeline — Anchorage Municipality, AK
Broccoli Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 10 | Apr 10 – Apr 24 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Direct Sow | May 1 | May 1 – May 22 |
| Harvest | July 17 | Jul 17 – Aug 28 |
| Fall Sowing | July 11 | Jul 11 – Jul 25 |
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 | — |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 5a
📆 Growing Season
127 days in Anchorage Municipality
Growing Tips for Broccoli in Anchorage Municipality
Direct sow Broccoli outdoors after May 15 in Anchorage Municipality when soil has warmed and frost danger has passed.
Common pests for Broccoli in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Anchorage Municipality receives only 20" of rain annually. Broccoli needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.
Broccoli in Other Locations
Frequently Asked Questions
When should I plant Broccoli in Anchorage Municipality, AK?
Anchorage Municipality is in Zone 5a with an average last frost of May 15. Plan your Broccoli 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 5a. The average last spring frost is May 15 and first fall frost is September 19.
Your Anchorage Municipality Garden Planner — Free
A 24-page printable planner built for Anchorage Municipality (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.