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When to plant Borage in Anchorage Municipality, AK

For Anchorage Municipality, gardeners: plant Borage May 1 through May 22 once soil reads 50°F. A second sowing from July 11 to July 25 extends the harvest into fall.

When to Plant Borage in Anchorage Municipality, AK

Anchorage Municipality, Alaska Zone 5a June

June in Anchorage Municipality, Alaska — your action list

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 15
Avg. first frost September 19
Soil temp (4") 56°F
Watering High
Pest pressure High
Daylight 18.9 hrs
  1. Sow borage in trays indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

July prep starts now
  • First harvests: borage
  • Fall sowing: borage

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Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.

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 Borage to ensure they mature before fall.

Anchorage Municipality, AK (Zone 5a) Short season
127 days
Last Spring Frost May 15
127 growing days
First Fall Frost September 19

Anchorage Municipality Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.5

Drainage

Well Drained

Borage Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Mar 30 Transplant: Apr 27 🍅 Harvest: Jun 22 – Aug 10
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Apr 10 Transplant: May 8 🍅 Harvest: Jul 3 – Aug 21
Safe Start (90%) ✓ Fits season (22 days to spare)
Start indoors: Apr 28 Transplant: May 26 🍅 Harvest: Jul 21 – Sep 8

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 Borage's growing requirements.

Soil pH

Your soil pH (4.9–6.5) is more acidic than Borage prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Anchorage Municipality is excellent for Borage — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Borage prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is excellent (5.2%) — Borage will thrive.

How to Plant Borage

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Borage

2
successive plantings in your 127-day season

Sow every 5.7 weeks. Last sowing by Jul 21 to harvest before frost.

For a dedicated fall crop, sow by Jul 11.

Borage Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Borage

Borage needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Borage Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.6" 0" ❄️ Dormant
May 2.2" 0.9" 1.3" 🚿 Regular watering
Jun 2.2" 1.5" 0.7" 💧 Light watering
Jul 2.2" 2.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3.3" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
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.

Borage 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.

Borage needs ~179 GDD — county provides 412 GDD Excellent fit

Borage Planting Timeline — Anchorage Municipality, AK

Borage Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 – Apr 24
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 1 May 1 – May 22
Harvest July 3 Jul 3 – Aug 21
Fall Sowing July 11 Jul 11 – Jul 25

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

127 days in Anchorage Municipality

Growing Tips for Borage in Anchorage Municipality

Direct sow Borage outdoors after May 15 in Anchorage Municipality when soil has warmed and frost danger has passed.

General growing tips

Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Borage in Anchorage Municipality, AK?

Anchorage Municipality is in Zone 5a with an average last frost of May 15. Plan your Borage 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.

When should I plant Borage in Anchorage Municipality, AK?

In Anchorage Municipality, AK, plant Borage after the last frost (around May 15) and before the first frost (around September 19). Best results when soil holds above 50°F.

What growing zone is Anchorage Municipality, AK for Borage?

Anchorage Municipality sits in USDA Zone 5a. Borage grows reliably in zones 3a through 11b, so it's a good fit here.

Can Borage grow in Anchorage Municipality's climate?

Yes — Borage grows well in Anchorage Municipality's temperate climate. Anchorage Municipality averages a 127-day frost-free season, with last frost around May 15 and first frost around September 19.

🌱

Your Anchorage Municipality Garden Planner — Free

A 22-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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Anchorage Municipality, AK. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.