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When to Plant Microgreens in Campbell County, WY

Campbell County, Wyoming Zone 5a May

May in Campbell County, Wyoming — your action list

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Campbell County, Wyoming.

Avg. last frost May 20
Avg. first frost September 20
Soil temp (4") 30°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Move microgreens from tray to bed

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Plant microgreens from seed, right in the garden

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

  3. Pick microgreens

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

Get ahead of 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.

Campbell County, Wyoming is in USDA Zone 5a. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.

At an elevation of 8,132 feet, Campbell County receives approximately 22.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Microgreens to ensure they mature before fall.

Campbell County, WY (Zone 5a) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20

Campbell County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: May 21 – Jun 18
Recommended (50%) ✓ Fits season (88 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: May 27 – Jun 24
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: May 3 Transplant: Jun 7 🍅 Harvest: Jun 14 – Jul 12

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 Campbell County

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

Soil pH

Your soil pH (6.7–7.6) is more alkaline than Microgreens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). 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

24
successive plantings in your 123-day season

Sow every 0.7 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Jul 12.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 313 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 1.7" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 2.7" 1.6" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.4" 1.9" 💧 Light watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Campbell 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 ~172 GDD — county provides 1,506 GDD Excellent fit

Microgreens Planting Timeline — Campbell County, WY

Microgreens Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 6 May 6 – May 27
Harvest May 27 May 27 – Jun 24
Fall Sowing July 12 Jul 12 – Jul 26

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 Transplant Outdoors Harvest
July Fall Sowing
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

123 days in Campbell County

Growing Tips for Microgreens in Campbell County

Direct sow Microgreens outdoors after May 20 in Campbell County when soil has warmed and frost danger has passed.

Your generous 123.0-day season in Campbell County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Campbell County 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 Campbell County, WY?

Campbell County is in Zone 5a with an average last frost of May 20. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Campbell County, WY?

Campbell County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 20 and first fall frost is September 20.

🌱

Your Campbell County Garden Planner — Free

A 24-page printable planner built for Campbell 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 Campbell County, WY. 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.