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When to Plant Microgreens in Gilliam County, OR

Gilliam County, Oregon Zone 7b May

Your May game plan for Gilliam County, Oregon

Each item below is timed to Gilliam County, Oregon's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 25
Avg. first frost October 15
Soil temp (4") 63°F
Watering High
Pest pressure Low
Daylight 14.7 hrs
  1. Start microgreens under lights

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Bring in the microgreens

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

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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.

Gilliam County, Oregon is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 15, giving you a growing season of approximately 173 days.

At an elevation of 965 feet, Gilliam County receives approximately 22.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Microgreens during the growing season.

Gilliam County, OR (Zone 7b) Moderate season
173 days
Last Spring Frost April 25
173 growing days
First Fall Frost October 15
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Gilliam County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (138 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Apr 22 – May 20
Recommended (50%) ✓ Fits season (138 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: May 2 – May 30
Safe Start (90%) ✓ Fits season (138 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: May 20 – Jun 17

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 Gilliam County

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

Soil pH

Your soil pH (5.3–6.7) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is excellent (4.5%) — Microgreens will thrive.

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

34
successive plantings in your 173-day season

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

For a dedicated fall crop, sow by Aug 06.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,164 gal / 100 sq ft

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 2.8" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 1.4" 2.9" 🚿 Regular watering
May 4.3" 1.4" 2.9" 🚿 Regular watering
Jun 4.3" 0.8" 3.5" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.5" 3.8" 🚿 Regular watering
Sep 4.3" 0.9" 3.4" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Gilliam 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 ~192 GDD — county provides 2,378 GDD Excellent fit

Microgreens Planting Timeline — Gilliam County, OR

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 11 Apr 11 – May 2
Harvest May 2 May 2 – May 30
Fall Sowing August 6 Aug 6 – Aug 20

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7b

📆 Growing Season

173 days in Gilliam County

Growing Tips for Microgreens in Gilliam County

Direct sow Microgreens outdoors after April 25 in Gilliam County when soil has warmed and frost danger has passed.

Your generous 173.0-day season in Gilliam County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Gilliam 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 Gilliam County, OR?

Gilliam County is in Zone 7b with an average last frost of April 25. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gilliam County, OR?

Gilliam County, Oregon is in USDA Hardiness Zone 7b. The average last spring frost is April 25 and first fall frost is October 15.

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Your Gilliam County Garden Planner — Free

A 24-page printable planner built for Gilliam County (Zone 7b). 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 Gilliam County, OR. 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.