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When to Plant Microgreens in Plumas County, CA

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.

Plumas County, California is in USDA Zone 6b. The average last spring frost is May 20 and the first fall frost is October 8, giving you a growing season of approximately 141 days.

At an elevation of 1,185 feet, Plumas County receives approximately 30.9 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Microgreens to ensure they mature before fall.

Plumas County, CA (Zone 6b) Short season
141 days
Last Spring Frost May 20
141 growing days
First Fall Frost October 8

Plumas County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (106 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: May 18 – Jun 15
Recommended (50%) ✓ Fits season (106 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: May 27 – Jun 24
Safe Start (90%) ✓ Fits season (111 days to spare)
Start indoors: May 4 Transplant: Jun 8 🍅 Harvest: Jun 15 – Jul 13

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 Plumas County

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

Soil pH

Your soil pH (6.6โ€“7.6) is more alkaline than Microgreens prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Plumas County is excellent for Microgreens โ€” 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 141-day season

Sow every 0.7 weeks. Last sowing by Sep 17 to harvest before frost.

For a dedicated fall crop, sow by Jul 30.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 120 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 6.9" 0" โ„๏ธ Dormant
Feb โ€” 6.2" 0" โ„๏ธ Dormant
Mar โ€” 5" 0" โ„๏ธ Dormant
Apr โ€” 2.4" 0" โ„๏ธ Dormant
May 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Jun 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Oct 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Nov โ€” 3" 0" โ„๏ธ Dormant
Dec โ€” 4.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Plumas County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~161 GDD — county provides 1,621 GDD Excellent fit

Microgreens Planting Timeline โ€” Plumas County, CA

Microgreens Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 โ€“ Apr 29
Transplant Outdoors May 20 May 20 โ€“ Jun 3
Direct Sow May 6 May 6 โ€“ May 27
Harvest May 27 May 27 โ€“ Jun 24
Fall Sowing July 30 Jul 30 โ€“ Aug 13

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

7โ€“21 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

141 days in Plumas County

Growing Tips for Microgreens in Plumas County

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

Your generous 141.0-day season in Plumas County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

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 Plumas County, CA?

Plumas County is in Zone 6b with an average last frost of May 20. Plan your Microgreens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Plumas County, CA?

Plumas County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 20 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Plumas County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Plumas County, CA. Local conditions may vary. Last updated: April 2026.