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When to Plant Microgreens in Lemhi County, ID

Lemhi County, Idaho Zone 5b May

What to do in May

Your garden in Lemhi County, Idaho is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost June 9
Avg. first frost September 14
Soil temp (4") 33°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Outdoor sowing time: microgreens

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

June will be here before you know it — start on
  • Transplants going out: 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.

Lemhi County, Idaho is in USDA Zone 5b. The average last spring frost is June 9 and the first fall frost is September 14, giving you a growing season of approximately 97 days.

At an elevation of 6,743 feet, Lemhi County receives approximately 12.6 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Microgreens to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Microgreens successfully. Mulch heavily to conserve soil moisture.

Lemhi County, ID (Zone 5b) Very short season
97 days
Last Spring Frost June 9
97 growing days
First Fall Frost September 14
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Lemhi County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: May 21 – Jun 18
Recommended (50%) ✓ Fits season (62 days to spare)
Start indoors: May 5 Transplant: Jun 9 🍅 Harvest: Jun 16 – Jul 14
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: May 21 Transplant: Jun 25 🍅 Harvest: Jul 2 – Jul 30

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 Lemhi County

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

Soil pH

Your soil pH (6.2–8.2) is more alkaline than Microgreens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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

19
successive plantings in your 97-day season

Sow every 0.7 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Jul 06.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 471 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.8" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 1.4" 0" ❄️ Dormant
Jun 4.3" 0.8" 3.5" 🚿 Regular watering
Jul 4.3" 1.3" 3" 🚿 Regular watering
Aug 4.3" 1.3" 3" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 1" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Lemhi 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 ~182 GDD — county provides 1,261 GDD Excellent fit

Microgreens Planting Timeline — Lemhi County, ID

Microgreens Planting Calendar

Activity When Date Range
Start Indoors May 5 May 5 – May 19
Transplant Outdoors June 9 Jun 9 – Jun 23
Direct Sow May 26 May 26 – Jun 16
Harvest June 16 Jun 16 – Jul 14
Fall Sowing July 6 Jul 6 – Jul 20

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5b

📆 Growing Season

97 days in Lemhi County

Growing Tips for Microgreens in Lemhi County

Direct sow Microgreens outdoors after June 09 in Lemhi County when soil has warmed and frost danger has passed.

Your generous 97.0-day season in Lemhi County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Lemhi County receives only 13" 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 Lemhi County, ID?

Lemhi County is in Zone 5b with an average last frost of June 9. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lemhi County, ID?

Lemhi County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is June 9 and first fall frost is September 14.

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Your Lemhi County Garden Planner — Free

A 24-page printable planner built for Lemhi County (Zone 5b). 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 Lemhi 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.