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When to plant Cosmos in Lafayette County, FL

The best window to plant Cosmos in Lafayette County, is February 4–February 25, when soil warms to 50°F. Last frost typically hits March 4; first frost November 26.

When to Plant Cosmos in Lafayette County, FL

Lafayette County, Florida Zone 9a June

What to do in June

Each item below is timed to Lafayette County, Florida's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 4
Avg. first frost November 26
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. It's harvest week for cosmos

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

Looking ahead to July
  • First harvests: cosmos

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Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.

Lafayette County, Florida is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 26, giving you a growing season of approximately 267 days.

At an elevation of 217 feet, Lafayette County receives approximately 57.2 inches of rainfall annually with predominantly sand soil. Summer highs average 94°F, providing good warmth for Cosmos during the growing season. Sandy soil warms quickly in spring — great for early planting — but Cosmos will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Lafayette County, FL (Zone 9a) Long season
267 days
Last Spring Frost March 4
267 growing days
First Fall Frost November 26

Lafayette County Soil Profile

Soil Type

Sand

Soil pH

5-6.2

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Jan 22 Transplant: Jan 22 🌸 Bloom: Apr 2 – Sep 17
Recommended (50%) ✓ Fits season (57 days to spare)
Start indoors: Feb 4 Transplant: Feb 4 🌸 Bloom: Apr 15 – Sep 30
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Feb 24 Transplant: Feb 24 🌸 Bloom: May 5 – Oct 20

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 Lafayette County

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Cosmos prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Cosmos.

Organic Matter

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

How to Plant Cosmos

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Cosmos

5
successive plantings in your 267-day season

Sow every 6.9 weeks. Last sowing by Aug 28 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 Cosmos

Cosmos 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 Cosmos Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 2.2" 3.4" 0" ✅ Rainfall sufficient
Apr 2.2" 2.8" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 8" 0" ✅ Rainfall sufficient
Jul 2.2" 7.7" 0" ✅ Rainfall sufficient
Aug 2.2" 8.5" 0" ✅ Rainfall sufficient
Sep 2.2" 6.9" 0" ✅ Rainfall sufficient
Oct 2.2" 5.6" 0" ✅ Rainfall sufficient
Nov 2.2" 2.4" 0" ✅ Rainfall sufficient
Dec 2.7" 0" ❄️ Dormant

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

Cosmos 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.

Cosmos needs ~1,538 GDD — county provides 5,473 GDD Excellent fit

Cosmos Planting Timeline — Lafayette County, FL

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors February 4 Feb 4 – Feb 18
Direct Sow February 4 Feb 4 – Feb 25
Bloom April 15 Apr 15 – Sep 30

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March
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

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

267 days in Lafayette County

Growing Tips for Cosmos in Lafayette County

Direct sow Cosmos outdoors after March 04 in Lafayette County when soil has warmed and frost danger has passed.

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

Common pests for Cosmos 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; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cosmos in Lafayette County, FL?

Lafayette County is in Zone 9a with an average last frost of March 4. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lafayette County, FL?

Lafayette County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 26.

When should I plant Cosmos in Lafayette County, FL?

In Lafayette County, FL, plant Cosmos after the last frost (around March 4) and before the first frost (around November 26). Best results when soil holds above 50°F.

What growing zone is Lafayette County, FL for Cosmos?

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

Can Cosmos grow in Lafayette County's climate?

Yes — Cosmos grows well in Lafayette County's temperate climate. Lafayette County averages a 267-day frost-free season, with last frost around March 4 and first frost around November 26.

🌱

Your Lafayette County Garden Planner — Free

A 22-page printable planner built for Lafayette County (Zone 9a). 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 Lafayette County, FL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.