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When to Plant Microgreens in Fremont County, ID

Fremont County, Idaho Zone 5a May

What to do in May

We've pulled the most time-sensitive tasks for Fremont County, Idaho this May and put them front and centre. Tackle them in order.

Avg. last frost June 12
Avg. first frost September 6
Soil temp (4") 41°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Put microgreens seeds straight in the ground

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

Looking ahead to June
  • Transplants going out: microgreens
  • First harvests: microgreens
  • Fall sowing: 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.

Fremont County, Idaho is in USDA Zone 5a. The average last spring frost is June 12 and the first fall frost is September 6, giving you a growing season of approximately 86 days.

At an elevation of 5,282 feet, Fremont County receives approximately 12.7 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.

Fremont County, ID (Zone 5a) Very short season
86 days
Last Spring Frost June 12
86 growing days
First Fall Frost September 6
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Fremont County Soil Profile

Soil Type

Loam

Soil pH

6.4-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Apr 18 Transplant: May 23 🍅 Harvest: May 30 – Jun 27
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: May 8 Transplant: Jun 12 🍅 Harvest: Jun 19 – Jul 17
Safe Start (90%) ✓ Fits season (63 days to spare)
Start indoors: May 23 Transplant: Jun 27 🍅 Harvest: Jul 4 – Aug 1

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 Fremont County

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

Soil pH

Your soil pH (6.4–8.0) is more alkaline than Microgreens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

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

16
successive plantings in your 86-day season

Sow every 0.7 weeks. Last sowing by Aug 16 to harvest before frost.

For a dedicated fall crop, sow by Jun 28.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 349 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 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 1.6" 0" ❄️ Dormant
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 1" 3.3" 🚿 Regular watering
Aug 4.3" 1.5" 2.8" 🚿 Regular watering
Sep 4.3" 1" 3.3" 🚿 Regular watering
Oct 1" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Fremont 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 1,118 GDD Excellent fit

Microgreens Planting Timeline — Fremont County, ID

Microgreens Planting Calendar

Activity When Date Range
Start Indoors May 8 May 8 – May 22
Transplant Outdoors June 12 Jun 12 – Jun 26
Direct Sow May 29 May 29 – Jun 19
Harvest June 19 Jun 19 – Jul 17
Fall Sowing June 28 Jun 28 – Jul 12

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 Fall Sowing 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 5a

📆 Growing Season

86 days in Fremont County

Growing Tips for Microgreens in Fremont County

Direct sow Microgreens outdoors after June 12 in Fremont County when soil has warmed and frost danger has passed.

Your generous 86.0-day season in Fremont County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Fremont 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 Fremont County, ID?

Fremont County is in Zone 5a with an average last frost of June 12. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fremont County, ID?

Fremont County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is June 12 and first fall frost is September 6.

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Your Fremont County Garden Planner — Free

A 24-page printable planner built for Fremont County (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 Fremont 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.