When to plant Cosmos in Monroe County, FL
Spring Cosmos in Monroe County goes in November 20–December 11, once nighttime temps stop dipping near freezing.
When to Plant Cosmos in Monroe County, FL
July to-do list for Monroe County, Florida
July is a pivotal month for Monroe County, Florida gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Bring in the cosmos
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
To set up a strong August, finish these tasks
- 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.
Monroe County, Florida is in USDA Zone 11b. The average last spring frost is January 22 and the first fall frost is April 15, giving you a growing season of approximately 83 days.
At an elevation of 169 feet, Monroe County receives approximately 55.6 inches of rainfall annually with predominantly sand soil. Summer highs average 93°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.
Monroe County Soil Profile
Soil Type
Sand
Soil pH
4.8-5.7
Drainage
Well Drained
Soil Compatibility in Monroe County
How your county's soil matches Cosmos's growing requirements.
Soil pH
Your soil pH (4.8–5.7) is more acidic than Cosmos prefers (6.0–8.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Monroe 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 (1.3%). Add 2-3 inches of compost before planting Cosmos.
How to Plant Cosmos
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 | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Feb | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 7.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.2" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 8.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 7.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jan–Oct in Monroe 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 — Monroe County, FL
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 25 | Dec 25 – Jan 8 |
| Transplant Outdoors | November 20 | Nov 20 – Dec 4 |
| Direct Sow | November 20 | Nov 20 – Dec 11 |
| Bloom | January 29 | Jan 29 – Sep 24 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Bloom |
| February | Bloom |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | Transplant Outdoors Direct Sow |
| December | Start Indoors Transplant Outdoors Direct Sow |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–8 · Your soil: too_acidic
🗺️ USDA Zone
Zone 11b
📆 Growing Season
365 days in Monroe County
Growing Tips for Cosmos in Monroe County
Direct sow Cosmos outdoors after January 22 in Monroe County when soil has warmed and frost danger has passed.
Sandy soil in Monroe 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 →
Cosmos in Other Locations
Frequently Asked Questions
When should I plant Cosmos in Monroe County, FL?
Monroe County is in Zone 11b with an average last frost of January 22. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Monroe County, FL?
Monroe County, Florida is in USDA Hardiness Zone 11b. The average last spring frost is January 22 and first fall frost is .
When should I plant Cosmos in Monroe County, FL?
In Monroe County, FL, plant Cosmos after the last frost (around January 1) and before the first frost (around December 31). Best results when soil holds above 50°F.
What growing zone is Monroe County, FL for Cosmos?
Monroe County sits in USDA Zone 11b. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Monroe County's climate?
Yes — Cosmos grows well in Monroe County's temperate climate. Monroe County averages a 365-day frost-free season, with last frost around January 1 and first frost around December 31.
Your Monroe County Garden Planner — Free
A 22-page printable planner built for Monroe County (Zone 11b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.