Blog

When to Plant Marigolds in Monroe County, FL

Monroe County, Florida Zone 11b May

Your May planting checklist for Monroe County, Florida

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

Avg. last frost January 22
Soil temp (4") 81°F
Watering Moderate
Pest pressure High
Daylight 13.2 hrs
  1. It's harvest week for marigolds

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

A few tasks this May that'll pay off in June
  • First harvests: marigolds

Instant PDF download. No spam, unsubscribe any time.

Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

Monroe County, Florida is in USDA Zone 11b. The average last spring frost is January 22 and the first fall frost is April 15, giving you a growing season of approximately 83 days.

At an elevation of 169 feet, Monroe County receives approximately 55.6 inches of rainfall annually with predominantly sand soil. Summer highs average 93°F, providing good warmth for Marigolds during the growing season. Sandy soil warms quickly in spring — great for early planting — but Marigolds will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Marigolds root diseases.

Monroe County, FL (Zone 11b) Very short season
83 days
Last Spring Frost January 22
83 growing days
First Fall Frost April 15
Share this guide:

Monroe County Soil Profile

Soil Type

Sand

Soil pH

4.8-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Start indoors: Feb 14 Transplant: Nov 15 🍅 Harvest: Jan 10 – Sep 5
Recommended (50%) ✓ Fits season (35 days to spare)
Start indoors: Feb 19 Transplant: Nov 20 🍅 Harvest: Jan 15 – Sep 10
Safe Start (90%) ✗ May not fit
Start indoors: Apr 13 Transplant: Jan 12 🍅 Harvest: Mar 9 – Nov 2

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 Monroe County

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

Soil pH

Your soil pH (4.8–5.7) is more acidic than Marigolds prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Marigolds.

Organic Matter

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

How to Plant Marigolds

0.3"
Planting Depth
10"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 33 gal / 100 sq ft

Monthly Watering Guide for Marigolds

Marigolds needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Marigolds Needs Rainfall You Supplement Action
Jan 2.2" 2.3" 0" ✅ Rainfall sufficient
Feb 2.2" 2.7" 0" ✅ Rainfall sufficient
Mar 2.2" 3.8" 0" ✅ Rainfall sufficient
Apr 2.2" 2.5" 0" ✅ Rainfall sufficient
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 7.1" 0" ✅ Rainfall sufficient
Jul 2.2" 8.2" 0" ✅ Rainfall sufficient
Aug 2.2" 8.7" 0" ✅ Rainfall sufficient
Sep 2.2" 7.7" 0" ✅ Rainfall sufficient
Oct 2.2" 4.8" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

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

Marigolds 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.

Marigolds needs ~1,185 GDD — county provides 7,208 GDD Excellent fit

Marigolds Planting Timeline — Monroe County, FL

Marigolds Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors November 20 Nov 20 – Dec 4
Direct Sow November 20 Nov 20 – Dec 11
Harvest January 15 Jan 15 – Sep 10

Plant 0.3" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Harvest
February Start Indoors Harvest
March Start Indoors Harvest
April Harvest
May Harvest
June Harvest
July Harvest
August Harvest
September Harvest
October
November Transplant Outdoors Direct Sow
December Transplant Outdoors Direct Sow
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 11b

📆 Growing Season

83 days in Monroe County

Growing Tips for Marigolds in Monroe County

Direct sow Marigolds outdoors after January 22 in Monroe County when soil has warmed and frost danger has passed.

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

Common pests for Marigolds in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

With 56" of annual rainfall in Monroe County, ensure good drainage for Marigolds — excess moisture can promote root rot and fungal diseases.

General growing tips

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Cabbage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Marigolds Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower heads dry on plant. Pull dried petals to reveal seeds.
Storage Store in envelopes; viable 3 years at 35°F, under 50% humidity.

Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.

Frequently Asked Questions

When should I plant Marigolds in Monroe County, FL?

Monroe County is in Zone 11b with an average last frost of January 22. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, FL?

Monroe County, Florida is in USDA Hardiness Zone 11b. The average last spring frost is January 22 and first fall frost is .

🌱

Your Monroe County Garden Planner — Free

A 24-page printable planner built for Monroe County (Zone 11b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Monroe 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.