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When to Plant Microgreens in Pinellas 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.

Pinellas County, Florida is in USDA Zone 9b. The average last spring frost is January 25 and the first fall frost is December 16, giving you a growing season of approximately 325 days.

At an elevation of 246 feet, Pinellas County receives approximately 58.1 inches of rainfall annually with predominantly sand soil. Summer highs average 102ยฐF, so Microgreens may need afternoon shade and extra watering during peak heat. 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.

Pinellas County, FL (Zone 9b) Year-round
325 days
Last Spring Frost January 25
325 growing days
First Fall Frost December 16

Pinellas County Soil Profile

Soil Type

Sand

Soil pH

5.1-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (290 days to spare)
Start indoors: Dec 22 Transplant: Jan 19 🍅 Harvest: Jan 26 – Feb 23
Recommended (50%) ✓ Fits season (290 days to spare)
Start indoors: Dec 28 Transplant: Jan 25 🍅 Harvest: Feb 1 – Mar 1
Safe Start (90%) ✓ Fits season (264 days to spare)
Start indoors: Jan 31 Transplant: Feb 28 🍅 Harvest: Mar 7 – Apr 4

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 Pinellas County

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

Soil pH

Your soil pH (5.1โ€“6.2) is more acidic than Microgreens prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Pinellas 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 (1.5%). 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.

Succession Planting Microgreens

64
successive plantings in your 325-day season

Sow every 0.7 weeks. Last sowing by Nov 25 to harvest before frost.

For a dedicated fall crop, sow by Oct 21.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,600 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" 3.2" 1.1" ๐Ÿ’ง Light watering
Mar 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Apr 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
May 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jun 4.3" 7.6" 0" โœ… Rainfall sufficient
Jul 4.3" 8.5" 0" โœ… Rainfall sufficient
Aug 4.3" 8.7" 0" โœ… Rainfall sufficient
Sep 4.3" 7.1" 0" โœ… Rainfall sufficient
Oct 4.3" 5.3" 0" โœ… Rainfall sufficient
Nov 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Dec 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Janโ€“Dec in Pinellas 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 ~371 GDD — county provides 8,639 GDD Excellent fit

Microgreens Planting Timeline โ€” Pinellas County, FL

Microgreens Planting Calendar

Activity When Date Range
Start Indoors December 28 Dec 28 โ€“ Jan 11
Transplant Outdoors January 25 Jan 25 โ€“ Feb 8
Direct Sow January 4 Jan 4 โ€“ Jan 25
Harvest February 1 Feb 1 โ€“ Mar 1
Fall Sowing October 21 Oct 21 โ€“ Nov 4

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

Month-by-Month Timeline

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

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 9b

๐Ÿ“† Growing Season

325 days in Pinellas County

Growing Tips for Microgreens in Pinellas County

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

Sandy soil in Pinellas 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.

With summer highs reaching 102ยฐF in Pinellas County, provide afternoon shade for Microgreens and water deeply in the morning.

Your generous 326.0-day season in Pinellas 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 Pinellas County, FL?

Pinellas County is in Zone 9b with an average last frost of January 25. Plan your Microgreens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pinellas County, FL?

Pinellas County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is January 25 and first fall frost is December 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pinellas County gardeners in Zone 9b 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 Pinellas County, FL. Local conditions may vary. Last updated: April 2026.