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When to plant Mint in Saint Augustine, FL

In Saint Augustine, Mint is a single-season spring crop — there's no second fall window. Plant February 16–March 2 for an 60–90-day harvest, finishing well before the December 2 first frost.

When to Plant Mint in Saint Augustine, FL

Mint
St. Johns County, Florida Zone 9b June

June to-do list for St. Johns County, Florida

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in St. Johns County, Florida.

Avg. last frost February 9
Avg. first frost December 2
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. It's harvest week for mint

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.

Saint Augustine, 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 57 feet, St. Johns County receives approximately 51.1 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Mint may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Mint will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mint root diseases.

Saint Augustine, FL (Zone 9b) Year-round
296 days
Last Spring Frost February 9
296 growing days
First Fall Frost December 2

Saint Augustine Soil Profile

Soil Type

Sand

Soil pH

4.9-6.1

Drainage

Well Drained

Mint Planting Risk Windows

Early Start (70% safe) ✓ Fits season (167 days to spare)
Transplant: Feb 1 🍅 Harvest: Apr 5 – Jun 14
Recommended (50%) ✓ Fits season (156 days to spare)
Transplant: Feb 16 🍅 Harvest: Apr 20 – Jun 29
Safe Start (90%) ✓ Fits season (147 days to spare)
Transplant: Mar 18 🍅 Harvest: May 20 – Jul 29

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 Saint Augustine

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

Soil pH

Your soil pH (4.9–6.1) is more acidic than Mint prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in St. Johns County warms quickly in spring but drains fast. Mint will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.5%). Add 2-3 inches of compost before planting Mint.

How to Plant Mint

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Mint

5
successive plantings in your 296-day season

Sow every 6.9 weeks. Last sowing by Sep 03 to harvest before frost.

Mint Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Mint

Mint needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mint Needs Rainfall You Supplement Action
Jan 2.4" 0" ❄️ Dormant
Feb 3" 2.4" 0.6" 💧 Light watering
Mar 3" 2.8" 0.2" 💧 Light watering
Apr 3" 2.8" 0.2" 💧 Light watering
May 3" 3.5" 0" ✅ Rainfall sufficient
Jun 3" 7" 0" ✅ Rainfall sufficient
Jul 3" 7.1" 0" ✅ Rainfall sufficient
Aug 3" 7.6" 0" ✅ Rainfall sufficient
Sep 3" 6.9" 0" ✅ Rainfall sufficient
Oct 3" 4.3" 0" ✅ Rainfall sufficient
Nov 3" 2.1" 0.9" 💧 Light watering
Dec 3" 2.3" 0.7" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in St. Johns County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Mint 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.

Mint needs ~1,819 GDD — county provides 7,202 GDD Excellent fit

Mint Planting Timeline — Saint Augustine, FL

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors February 16 Feb 16 – Mar 2
Harvest April 20 Apr 20 – Jun 29

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March Transplant Outdoors
April Harvest
May Harvest
June Harvest
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

296 days in St. Johns County

Growing Tips for Mint in Saint Augustine

Direct sow Mint outdoors after February 09 in St. Johns County when soil has warmed and frost danger has passed.

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

With summer highs reaching 99°F in St. Johns County, provide afternoon shade for Mint and water deeply in the morning.

General growing tips

Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.

Companion Planting

Good Companions

Avoid Planting Near

  • Parsley

Check more plant combinations with our Companion Planting Checker →

When should I plant Mint in Saint Augustine, FL?

In Saint Augustine, FL, plant Mint after the last frost (around February 9) and before the first frost (around December 2). Best results when soil holds above 50°F.

What growing zone is Saint Augustine, FL for Mint?

Saint Augustine sits in USDA Zone 9b. Mint grows reliably in zones 3a through 10b, so it's a good fit here.

Can Mint grow in Saint Augustine's climate?

Yes — Mint grows well in Saint Augustine's temperate climate. Saint Augustine averages a 297-day frost-free season, with last frost around February 9 and first frost around December 2.

🌱

Your St. Johns County Garden Planner — Free

A 22-page printable planner built for St. Johns 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 St. Johns County, FL. Local conditions may vary. Last updated: June 2026.