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When to Plant Microgreens in Putnam County, FL

Putnam County, Florida Zone 9b May

May to-do list for Putnam County, Florida

May is a pivotal month for Putnam County, Florida gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 9
Avg. first frost December 2
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs

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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.

Putnam County, Florida is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.

At an elevation of 278 feet, Putnam County receives approximately 57.5 inches of rainfall annually with predominantly sand soil. Summer highs average 95°F, so Microgreens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — 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.

Putnam County, FL (Zone 9b) Year-round
296 days
Last Spring Frost February 9
296 growing days
First Fall Frost December 2
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Putnam County Soil Profile

Soil Type

Sand

Soil pH

4.9-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (269 days to spare)
Start indoors: Dec 28 Transplant: Jan 25 🍅 Harvest: Feb 1 – Mar 1
Recommended (50%) ✓ Fits season (261 days to spare)
Start indoors: Jan 12 Transplant: Feb 9 🍅 Harvest: Feb 16 – Mar 16
Safe Start (90%) ✓ Fits season (262 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: Mar 11 – Apr 8

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 Putnam County

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

Soil pH

Your soil pH (4.9–6.2) is more acidic than Microgreens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Putnam 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 (1.4%). 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

58
successive plantings in your 296-day season

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

For a dedicated fall crop, sow by Oct 07.

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 1,544 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 2.4" 0" ❄️ Dormant
Feb 4.3" 2.6" 1.7" 💧 Light watering
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 7.9" 0" ✅ Rainfall sufficient
Jul 4.3" 9.4" 0" ✅ Rainfall sufficient
Aug 4.3" 8.7" 0" ✅ Rainfall sufficient
Sep 4.3" 7.4" 0" ✅ Rainfall sufficient
Oct 4.3" 5.3" 0" ✅ Rainfall sufficient
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 4.3" 2.6" 1.7" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Putnam 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 ~298 GDD — county provides 6,311 GDD Excellent fit

Microgreens Planting Timeline — Putnam County, FL

Microgreens Planting Calendar

Activity When Date Range
Start Indoors January 12 Jan 12 – Jan 26
Transplant Outdoors February 9 Feb 9 – Feb 23
Direct Sow January 19 Jan 19 – Feb 9
Harvest February 16 Feb 16 – Mar 16
Fall Sowing October 7 Oct 7 – Oct 21

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

296 days in Putnam County

Growing Tips for Microgreens in Putnam County

Direct sow Microgreens outdoors after February 09 in Putnam County when soil has warmed and frost danger has passed.

Sandy soil in Putnam County dries quickly — mulch Microgreens with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 297.0-day season in Putnam 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 Putnam County, FL?

Putnam County is in Zone 9b with an average last frost of February 9. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Putnam County, FL?

Putnam County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 2.

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Your Putnam County Garden Planner — Free

A 24-page printable planner built for Putnam County (Zone 9b). 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 Putnam County, FL. 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.