When to plant Cosmos in Washington County County,
Washington County County's spring Cosmos window runs February 5 through February 26. aim for a steady week of warm soil before planting.
When to Plant Cosmos in Washington County, FL
Your June game plan for Washington County, Florida
Welcome to June in Zone 9a. These are the moves that will have the biggest impact on your growing season.
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Start harvesting cosmos
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Coming up in July — start thinking about
- First harvests: cosmos
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.
Washington County, Florida is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 20, giving you a growing season of approximately 260 days.
At an elevation of 196 feet, Washington County receives approximately 50.6 inches of rainfall annually with predominantly sand soil. Summer highs average 97°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.
Washington County Soil Profile
Soil Type
Sand
Soil pH
4.8-5.9
Drainage
Well Drained
Cosmos Planting Risk Windows
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 Washington County
How your county's soil matches Cosmos's growing requirements.
Soil pH
Your soil pH (4.8–5.9) is more acidic than Cosmos prefers (6.0–8.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Washington 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 (1.7%). Add 2-3 inches of compost before planting Cosmos.
How to Plant Cosmos
Succession Planting Cosmos
Sow every 6.9 weeks. Last sowing by Aug 22 to harvest before frost.
Cosmos Water Budget
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" | 0" | ❄️ Dormant |
| Feb | — | 2.8" | 0" | ❄️ Dormant |
| Mar | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 6.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 6.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 7.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Washington 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 Planting Timeline — Washington County, FL
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 5 | Feb 5 – Feb 19 |
| Transplant Outdoors | February 5 | Feb 5 – Feb 19 |
| Direct Sow | February 5 | Feb 5 – Feb 26 |
| Bloom | April 16 | Apr 16 – Oct 1 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | — |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| 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
260 days in Washington County
Growing Tips for Cosmos in Washington County
Direct sow Cosmos outdoors after March 05 in Washington County when soil has warmed and frost danger has passed.
Sandy soil in Washington County dries quickly — mulch Cosmos with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 97°F in Washington County, provide afternoon shade for Cosmos and water deeply in the morning.
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 →
Cosmos in Other Locations
Frequently Asked Questions
When should I plant Cosmos in Washington County, FL?
Washington County is in Zone 9a with an average last frost of March 5. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, FL?
Washington County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 20.
When should I plant Cosmos in Washington County, ?
In Washington County, , plant Cosmos after the last frost (around March 5) and before the first frost (around November 20). Best results when soil holds above 50°F.
What growing zone is Washington County, for Cosmos?
Washington 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 Washington County's climate?
Yes — Cosmos grows well in Washington County's temperate climate. Washington County averages a 260-day frost-free season, with last frost around March 5 and first frost around November 20.
Your Washington County Garden Planner — Free
A 22-page printable planner built for Washington 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.