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When to Plant Microgreens in Miami-Dade County, FL

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.

Miami-Dade County, Florida is in USDA Zone 10b. The average last spring frost is January 1 and the first fall frost is December 31, giving you a growing season of approximately 364 days.

At an elevation of 123 feet, Miami-Dade County receives approximately 58.7 inches of rainfall annually with predominantly sand soil. Summer highs average 90ยฐF, providing good warmth for Microgreens during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Microgreens will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Microgreens root diseases.

Miami-Dade County, FL (Zone 10b) Year-round
364 days
Last Spring Frost January 1
364 growing days
First Fall Frost December 31

Miami-Dade County Soil Profile

Soil Type

Sand

Soil pH

5.1-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (148 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: Apr 22 – May 20
Recommended (50%) ✓ Fits season (148 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: Apr 22 – May 20
Safe Start (90%) ✓ Fits season (148 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: Apr 22 – May 20

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 Miami-Dade County

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

Soil pH

Your soil pH (5.1โ€“6.3) is more acidic than Microgreens prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Miami-Dade County warms quickly in spring but drains fast. Microgreens will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Microgreens.

How to Plant Microgreens

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 2,029 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 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Feb 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Mar 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Apr 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
May 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Jun 4.3" 8.1" 0" โœ… Rainfall sufficient
Jul 4.3" 9.5" 0" โœ… Rainfall sufficient
Aug 4.3" 8.6" 0" โœ… Rainfall sufficient
Sep 4.3" 7.1" 0" โœ… Rainfall sufficient
Oct 4.3" 5" 0" โœ… Rainfall sufficient
Nov 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Dec 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Janโ€“Dec in Miami-Dade 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 ~245 GDD — county provides 6,387 GDD Excellent fit

Microgreens Planting Timeline โ€” Miami-Dade County, FL

Microgreens Planting Calendar

Activity When Date Range
Start Indoors December 4 Dec 4 โ€“ Dec 18
Transplant Outdoors January 1 Jan 1 โ€“ Jan 15
Direct Sow December 11 Dec 11 โ€“ Jan 1
Harvest January 8 Jan 8 โ€“ Feb 5
Fall Sowing November 5 Nov 5 โ€“ Nov 19

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

7โ€“21 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 10b

๐Ÿ“† Growing Season

364 days in Miami-Dade County

Growing Tips for Microgreens in Miami-Dade County

Sandy soil in Miami-Dade County dries quickly โ€” mulch Microgreens with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 365.0-day season in Miami-Dade 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 Miami-Dade County, FL?

Miami-Dade County is in Zone 10b with an average last frost of January 1. Plan your Microgreens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Miami-Dade County, FL?

Miami-Dade County, Florida is in USDA Hardiness Zone 10b. The average last spring frost is January 1 and first fall frost is December 31.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Miami-Dade County gardeners in Zone 10b 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 Miami-Dade County, FL. Local conditions may vary. Last updated: April 2026.