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When to plant Marigolds in St. Johns County, FL

St. Johns County sits in USDA Zone 9b. Plant Marigolds between January 19 (after last frost on February 9) and February 9.

When to Plant Marigolds in St. Johns County, FL

St. Johns County, Florida Zone 9b June

This month in St. Johns County, Florida

We've pulled the most time-sensitive tasks for St. Johns County, Florida this June and put them front and centre. Tackle them in order.

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. Basket week: marigolds

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

A few tasks this June that'll pay off in July
  • 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.

St. Johns 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 57 feet, St. Johns County receives approximately 51.1 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Marigolds may need afternoon shade and extra watering during peak heat. 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.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
St. Johns County, FL (Zone 9b) Year-round
296 days
Last Spring Frost February 9
296 growing days
First Fall Frost December 2

St. Johns County Soil Profile

Soil Type

Sand

Soil pH

4.9-6.1

Drainage

Well Drained

Marigolds Planting Risk Windows

Early Start (70% safe) ✓ Fits season (97 days to spare)
Start indoors: Dec 21 Transplant: Jan 4 🌸 Bloom: Mar 1 – Aug 23
Recommended (50%) ✓ Fits season (86 days to spare)
Start indoors: Jan 5 Transplant: Jan 19 🌸 Bloom: Mar 16 – Sep 7
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Feb 4 Transplant: Feb 18 🌸 Bloom: Apr 15 – Oct 7

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 St. Johns County

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

Soil pH

Your soil pH (4.9–6.1) is more acidic than Marigolds prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in St. Johns County warms quickly in spring but drains fast. Marigolds 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 Marigolds.

How to Plant Marigolds

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

Succession Planting Marigolds

7
successive plantings in your 296-day season

Sow every 5.7 weeks. Last sowing by Sep 23 to harvest before frost.

Marigolds 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 2.4" 0" ❄️ Dormant
Feb 2.2" 2.4" 0" ✅ Rainfall sufficient
Mar 2.2" 2.8" 0" ✅ Rainfall sufficient
Apr 2.2" 2.8" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 7" 0" ✅ Rainfall sufficient
Jul 2.2" 7.1" 0" ✅ Rainfall sufficient
Aug 2.2" 7.6" 0" ✅ Rainfall sufficient
Sep 2.2" 6.9" 0" ✅ Rainfall sufficient
Oct 2.2" 4.3" 0" ✅ Rainfall sufficient
Nov 2.2" 2.1" 0.1" 💧 Light watering
Dec 2.2" 2.3" 0" ✅ Rainfall sufficient

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.

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 ~1,455 GDD — county provides 7,202 GDD Excellent fit

Marigolds Planting Timeline — St. Johns County, FL

Marigolds Planting Calendar

Activity When Date Range
Start Indoors January 5 Jan 5 – Jan 19
Transplant Outdoors January 19 Jan 19 – Feb 2
Direct Sow January 19 Jan 19 – Feb 9
Bloom March 16 Mar 16 – Sep 7

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

Month-by-Month Timeline

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

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 9b

📆 Growing Season

296 days in St. Johns County

Growing Tips for Marigolds in St. Johns County

Direct sow Marigolds 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 Marigolds 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 Marigolds and water deeply in the morning.

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

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 St. Johns County, FL?

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

What planting zone is St. Johns County, FL?

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

When should I plant Marigolds in St. Johns County, FL?

In St. Johns County, FL, plant Marigolds 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 St. Johns County, FL for Marigolds?

St. Johns County sits in USDA Zone 9b. Marigolds grows reliably in zones 2a through 11b, so it's a good fit here.

Can Marigolds grow in St. Johns County's climate?

Yes — Marigolds grows well in St. Johns County's temperate climate. St. Johns County 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.

Sources & credits

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