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When to Plant Microgreens in Latah County, ID

Latah County, Idaho Zone 6b May

May in the garden — Latah County, Idaho

Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 11
Avg. first frost September 23
Soil temp (4") 41°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
  1. Transplant microgreens outside

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Start harvesting microgreens

    If you can't use it all right away, check the food-preservation section of your planner.

A few tasks this May that'll pay off in June
  • Starting indoors: microgreens
  • First harvests: microgreens

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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.

Latah County, Idaho is in USDA Zone 6b. The average last spring frost is May 11 and the first fall frost is September 23, giving you a growing season of approximately 135 days.

At an elevation of 5,530 feet, Latah County receives approximately 14.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Microgreens during the growing season. With low rainfall, drip irrigation is essential for growing Microgreens successfully. Mulch heavily to conserve soil moisture.

Latah County, ID (Zone 6b) Short season
135 days
Last Spring Frost May 11
135 growing days
First Fall Frost September 23

Latah County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (100 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: May 11 – Jun 8
Recommended (50%) ✓ Fits season (100 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: May 18 – Jun 15
Safe Start (90%) ✓ Fits season (97 days to spare)
Start indoors: May 1 Transplant: Jun 5 🍅 Harvest: Jun 12 – Jul 10

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 Latah County

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

Soil pH

Your soil pH (6.7–8.0) is more alkaline than Microgreens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Latah County is excellent for Microgreens — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Microgreens.

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

26
successive plantings in your 135-day season

Sow every 0.7 weeks. Last sowing by Sep 02 to harvest before frost.

For a dedicated fall crop, sow by Jul 15.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,210 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Latah County). 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 ~203 GDD — county provides 1,957 GDD Excellent fit

Microgreens Planting Timeline — Latah County, ID

Microgreens Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 – Apr 20
Transplant Outdoors May 11 May 11 – May 25
Direct Sow April 27 Apr 27 – May 18
Harvest May 18 May 18 – Jun 15
Fall Sowing July 15 Jul 15 – Jul 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

135 days in Latah County

Growing Tips for Microgreens in Latah County

Direct sow Microgreens outdoors after May 11 in Latah County when soil has warmed and frost danger has passed.

Your generous 135.0-day season in Latah County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Latah County receives only 15" 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 Latah County, ID?

Latah County is in Zone 6b with an average last frost of May 11. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Latah County, ID?

Latah County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 11 and first fall frost is September 23.

🌱

Your Latah County Garden Planner — Free

A 24-page printable planner built for Latah County (Zone 6b). 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 Latah County, ID. 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.