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When to Plant Microgreens in Cobb County, GA

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.

Cobb County, Georgia is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 1, giving you a growing season of approximately 215 days.

At an elevation of 387 feet, Cobb County receives approximately 57.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89ยฐF, providing good warmth for Microgreens during the growing season. Clay soil retains moisture well for Microgreens, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Microgreens root diseases.

Cobb County, GA (Zone 7b) Long season
215 days
Last Spring Frost March 31
215 growing days
First Fall Frost November 1

Cobb County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (182 days to spare)
Start indoors: Feb 16 Transplant: Mar 23 🍅 Harvest: Mar 30 – Apr 27
Recommended (50%) ✓ Fits season (180 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: Apr 7 – May 5
Safe Start (90%) ✓ Fits season (185 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Apr 24 – May 22

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 Cobb County

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

Soil pH

Your soil pH (5.3โ€“6.5) is more acidic than Microgreens prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Cobb County is excellent for Microgreens โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is moderate (2.3%). 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

42
successive plantings in your 215-day season

Sow every 0.7 weeks. Last sowing by Oct 11 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 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€” 4.2" 0" โ„๏ธ Dormant
Feb โ€” 4" 0" โ„๏ธ Dormant
Mar 4.3" 6" 0" โœ… Rainfall sufficient
Apr 4.3" 4.7" 0" โœ… Rainfall sufficient
May 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jun 4.3" 5.8" 0" โœ… Rainfall sufficient
Jul 4.3" 5.5" 0" โœ… Rainfall sufficient
Aug 4.3" 5.2" 0" โœ… Rainfall sufficient
Sep 4.3" 4.7" 0" โœ… Rainfall sufficient
Oct 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Nov 4.3" 4.3" 0" โœ… Rainfall sufficient
Dec โ€” 5.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Cobb 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 ~234 GDD — county provides 3,601 GDD Excellent fit

Microgreens Planting Timeline โ€” Cobb County, GA

Microgreens Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 โ€“ Mar 10
Transplant Outdoors March 31 Mar 31 โ€“ Apr 14
Direct Sow March 17 Mar 17 โ€“ Apr 7
Harvest April 7 Apr 7 โ€“ May 5
Fall Sowing August 23 Aug 23 โ€“ Sep 6

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

7โ€“21 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

215 days in Cobb County

Growing Tips for Microgreens in Cobb County

Direct sow Microgreens outdoors after March 31 in Cobb County when soil has warmed and frost danger has passed.

With Cobb County's clay soil (26% clay), work in 3-4 inches of compost before planting Microgreens. Avoid tilling when soil is wet to prevent compaction.

Your generous 215.0-day season in Cobb 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 Cobb County, GA?

Cobb County is in Zone 7b with an average last frost of March 31. Plan your Microgreens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cobb County, GA?

Cobb County, Georgia is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Cobb County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Cobb County, GA. Local conditions may vary. Last updated: April 2026.