Blog

When to plant Cosmos in Flagler County, FL

Spring Cosmos in Flagler County goes in January 1–January 22, once nighttime temps stop dipping near freezing.

When to Plant Cosmos in Flagler County, FL

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.

Flagler County, Florida is in USDA Zone 9b. The average last spring frost is February 5 and the first fall frost is December 17, giving you a growing season of approximately 315 days.

At an elevation of 134 feet, Flagler County receives approximately 54.2 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Cosmos may need afternoon shade and extra watering during peak heat. 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
Flagler County, FL (Zone 9b) Year-round
315 days
Last Spring Frost February 5
315 growing days
First Fall Frost December 17

Flagler County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.7

Drainage

Well Drained

Monthly Watering Guide for Cosmos

Cosmos needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cosmos Needs Rainfall You Supplement Action
Jan 2.7" 0" ❄️ Dormant
Feb 4.3" 2.5" 1.8" 💧 Light watering
Mar 4.3" 3" 1.3" 💧 Light watering
Apr 4.3" 2.2" 2.1" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 8.8" 0" ✅ Rainfall sufficient
Jul 4.3" 7.7" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 6.9" 0" ✅ Rainfall sufficient
Oct 4.3" 4.7" 0" ✅ Rainfall sufficient
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 4.3" 2.5" 1.8" 💧 Light watering

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

Cosmos Planting Timeline — Flagler County, FL

Cosmos Planting Calendar

Activity When Date Range
Start Indoors January 8 Jan 8 – Jan 22
Transplant Outdoors January 1 Jan 1 – Jan 15
Direct Sow January 1 Jan 1 – Jan 22
Bloom March 12 Mar 12 – Sep 10

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

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors Direct Sow
February
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

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

315 days in Flagler County

Growing Tips for Flagler County

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 Flagler County, FL?

Flagler County is in Zone 9b with an average last frost of February 5. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Flagler County, FL?

Flagler County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 5 and first fall frost is December 17.

When should I plant Cosmos in Flagler County, FL?

In Flagler County, FL, plant Cosmos after the last frost (around February 5) and before the first frost (around December 17). Best results when soil holds above 50°F.

What growing zone is Flagler County, FL for Cosmos?

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

Can Cosmos grow in Flagler County's climate?

Yes — Cosmos grows well in Flagler County's temperate climate. Flagler County averages a 316-day frost-free season, with last frost around February 5 and first frost around December 17.

🌱

Your Flagler County Garden Planner — Free

A 22-page printable planner built for Flagler 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.

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 Flagler County, FL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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