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When to Plant Microgreens in Sitka City and Borough, AK

Sitka City and Borough, Alaska Zone 7b May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Sitka City and Borough, Alaska.

Avg. last frost April 20
Avg. first frost October 24
Soil temp (4") 64°F
Watering Critical
Pest pressure Moderate
Daylight 16.2 hrs
  1. Start microgreens under lights

    You're about 22 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Bring in the microgreens

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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Microgreens are young seedlings of vegetables and herbs harvested at the cotyledon or first true leaf stage. They pack concentrated flavors and nutrients in a tiny package.

Sitka City and Borough, Alaska is in USDA Zone 7b. The average last spring frost is April 20 and the first fall frost is October 24, giving you a growing season of approximately 187 days.

At an elevation of 1,935 feet, Sitka City and Borough receives approximately 21.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 69°F, so choose short-season varieties of Microgreens to ensure they mature before fall.

Sitka City and Borough, AK (Zone 7b) Moderate season
187 days
Last Spring Frost April 20
187 growing days
First Fall Frost October 24

Sitka City and Borough Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (154 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: Apr 19 – May 17
Recommended (50%) ✓ Fits season (152 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🍅 Harvest: Apr 27 – May 25
Safe Start (90%) ✓ Fits season (146 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: May 20 – Jun 17

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 Sitka City and Borough

How your county's soil matches Microgreens's growing requirements.

Soil pH

Your soil pH (4.9–6.4) is more acidic than Microgreens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Sitka City and Borough is excellent for Microgreens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.5%) — Microgreens will thrive.

How to Plant Microgreens

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

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

Succession Planting Microgreens

37
successive plantings in your 187-day season

Sow every 0.7 weeks. Last sowing by Oct 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 849 gal / 100 sq ft

Monthly Watering Guide for Microgreens

Microgreens needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Microgreens Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 0.7" 0" ❄️ Dormant
Apr 4.3" 0.6" 3.7" 🚿 Regular watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2.8" 1.5" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sitka City and Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Microgreens 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.

Microgreens needs ~24 GDD — county provides 327 GDD Excellent fit

Microgreens Planting Timeline — Sitka City and Borough, AK

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 6 Apr 6 – Apr 27
Harvest April 27 Apr 27 – May 25
Fall Sowing August 15 Aug 15 – Aug 29

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow Harvest
May Transplant Outdoors Harvest
June
July
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

187 days in Sitka City and Borough

Growing Tips for Microgreens in Sitka City and Borough

Direct sow Microgreens outdoors after April 20 in Sitka City and Borough when soil has warmed and frost danger has passed.

Your generous 187.0-day season in Sitka City and Borough allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Sitka City and Borough receives only 22" of rain annually. Microgreens needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Sow seeds densely on shallow trays of moist growing medium. Cover until germination, then provide light. Harvest with scissors when 1-3 inches tall. Grow year-round indoors.

Frequently Asked Questions

When should I plant Microgreens in Sitka City and Borough, AK?

Sitka City and Borough is in Zone 7b with an average last frost of April 20. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sitka City and Borough, AK?

Sitka City and Borough, Alaska is in USDA Hardiness Zone 7b. The average last spring frost is April 20 and first fall frost is October 24.

🌱

Your Sitka City and Borough Garden Planner — Free

A 24-page printable planner built for Sitka City and Borough (Zone 7b). 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 Sitka City and Borough, AK. Local conditions may vary. Last updated: May 2026.

Sources & credits

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