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When to Plant Marigolds in Martin County, FL

Martin County, Florida Zone 10b May

May in the garden — Martin County, Florida

Your Martin County, Florida garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost January 25
Avg. first frost December 13
Soil temp (4") 80°F
Watering Moderate
Pest pressure High
Daylight 13.3 hrs
  1. Collect marigolds at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Looking ahead to June
  • First harvests: marigolds

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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.

Martin County, Florida is in USDA Zone 10b. The average last spring frost is January 25 and the first fall frost is December 13, giving you a growing season of approximately 322 days.

At an elevation of 80 feet, Martin County receives approximately 56.3 inches of rainfall annually with predominantly sand soil. Summer highs average 88°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.

Martin County, FL (Zone 10b) Year-round
322 days
Last Spring Frost January 25
322 growing days
First Fall Frost December 13
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Martin County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Feb 12 Transplant: Dec 4 🍅 Harvest: Jan 29 – Aug 27
Recommended (50%) ✓ Fits season (98 days to spare)
Start indoors: Feb 22 Transplant: Dec 14 🍅 Harvest: Feb 8 – Sep 6
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 17 Transplant: Jan 6 🍅 Harvest: Mar 3 – Sep 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 Martin County

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

Soil pH

Your soil pH (5.1–5.7) is more acidic than Marigolds prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Martin 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 (1.5%). Add 2-3 inches of compost before planting Marigolds.

How to Plant Marigolds

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

Succession Planting Marigolds

7
successive plantings in your 322-day season

Sow every 5.7 weeks. Last sowing by Oct 04 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/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 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" 2.8" 0" ✅ Rainfall sufficient
Feb 2.2" 3.1" 0" ✅ Rainfall sufficient
Mar 2.2" 3" 0" ✅ Rainfall sufficient
Apr 2.2" 2.3" 0" ✅ Rainfall sufficient
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 8.6" 0" ✅ Rainfall sufficient
Jul 2.2" 7.9" 0" ✅ Rainfall sufficient
Aug 2.2" 8.4" 0" ✅ Rainfall sufficient
Sep 2.2" 8.2" 0" ✅ Rainfall sufficient
Oct 2.2" 4.2" 0" ✅ Rainfall sufficient
Nov 2.2" 2.2" 0" ✅ Rainfall sufficient
Dec 2.2" 2.1" 0.1" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Martin 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 ~960 GDD — county provides 5,168 GDD Excellent fit

Marigolds Planting Timeline — Martin County, FL

Marigolds Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors December 14 Dec 14 – Dec 28
Direct Sow December 14 Dec 14 – Jan 4
Harvest February 8 Feb 8 – Sep 6

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 10b

📆 Growing Season

322 days in Martin County

Growing Tips for Marigolds in Martin County

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

Sandy soil in Martin 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 Martin 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 Martin County, FL?

Martin County is in Zone 10b with an average last frost of January 25. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Martin County, FL?

Martin County, Florida is in USDA Hardiness Zone 10b. The average last spring frost is January 25 and first fall frost is December 13.

🌱

Your Martin County Garden Planner — Free

A 24-page printable planner built for Martin County (Zone 10b). 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 Martin 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.