Blog

When to Plant Microgreens in Cassia County, ID

Cassia County, Idaho Zone 6b May

Your May gardening checklist

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

Avg. last frost May 15
Avg. first frost October 1
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Plant out microgreens

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Scatter microgreens into prepared beds

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

  3. Collect microgreens at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of June
  • Starting indoors: microgreens
  • First harvests: microgreens

Instant PDF download. No spam, unsubscribe any time.

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.

Cassia County, Idaho is in USDA Zone 6b. The average last spring frost is May 15 and the first fall frost is October 1, giving you a growing season of approximately 139 days.

At an elevation of 8,089 feet, Cassia County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87°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.

Cassia County, ID (Zone 6b) Short season
139 days
Last Spring Frost May 15
139 growing days
First Fall Frost October 1

Cassia County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: May 16 – Jun 13
Recommended (50%) ✓ Fits season (104 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: May 22 – Jun 19
Safe Start (90%) ✓ Fits season (97 days to spare)
Start indoors: May 5 Transplant: Jun 9 🍅 Harvest: Jun 16 – Jul 14

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 Cassia County

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

Soil pH

Your soil pH (6.3–8.2) is more alkaline than Microgreens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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

27
successive plantings in your 139-day season

Sow every 0.7 weeks. Last sowing by Sep 10 to harvest before frost.

For a dedicated fall crop, sow by Jul 23.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 700 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 1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.1" 3.2" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 4.3" 1.6" 2.7" 🚿 Regular watering
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Cassia 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 ~214 GDD — county provides 2,119 GDD Excellent fit

Microgreens Planting Timeline — Cassia County, ID

Microgreens Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 – Apr 24
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 1 May 1 – May 22
Harvest May 22 May 22 – Jun 19
Fall Sowing July 23 Jul 23 – Aug 6

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow Harvest
June Harvest
July Fall Sowing
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_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

139 days in Cassia County

Growing Tips for Microgreens in Cassia County

Direct sow Microgreens outdoors after May 15 in Cassia County when soil has warmed and frost danger has passed.

Your generous 139.0-day season in Cassia County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Cassia County receives only 18" 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 Cassia County, ID?

Cassia County is in Zone 6b with an average last frost of May 15. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cassia County, ID?

Cassia County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 15 and first fall frost is October 1.

🌱

Your Cassia County Garden Planner — Free

A 24-page printable planner built for Cassia 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Cassia 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.