When to plant Cosmos in Franklin County County,
Plant Cosmos in Franklin County County from April 12 to May 3 in spring. Franklin County County sits in USDA Zone 6b, with last frost around April 12 and first frost on October 25.
When to Plant Cosmos in Franklin County, KS
Your June gardening checklist
We've pulled the most time-sensitive tasks for Franklin County, Kansas this June and put them front and centre. Tackle them in order.
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Bring in the cosmos
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Looking ahead to July
- 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.
Franklin County, Kansas is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 25, giving you a growing season of approximately 196 days.
At an elevation of 834 feet, Franklin County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Cosmos during the growing season.
Franklin County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.2
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 Franklin County
How your county's soil matches Cosmos's growing requirements.
Soil pH
Your soil pH (6.3–7.2) is within Cosmos's preferred range (6.0–8.0).
Soil Texture
The loam soil in Franklin County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Cosmos will thrive.
How to Plant Cosmos
Succession Planting Cosmos
Sow every 6.9 weeks. Last sowing by Jul 27 to harvest before frost.
Cosmos Water Budget
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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Franklin 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 — Franklin County, KS
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 15 | Mar 15 – Mar 29 |
| Transplant Outdoors | April 12 | Apr 12 – Apr 26 |
| Direct Sow | April 12 | Apr 12 – May 3 |
| Bloom | June 21 | Jun 21 – Oct 4 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Direct Sow |
| 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: ideal
🗺️ USDA Zone
Zone 6b
📆 Growing Season
196 days in Franklin County
Growing Tips for Cosmos in Franklin County
Direct sow Cosmos outdoors after April 12 in Franklin County when soil has warmed and frost danger has passed.
Common pests for Cosmos in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
Franklin County receives only 24" of rain annually. Cosmos needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Franklin County, KS?
Franklin County is in Zone 6b with an average last frost of April 12. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Franklin County, KS?
Franklin County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 25.
When should I plant Cosmos in Franklin County County, ?
In Franklin County County, , plant Cosmos after the last frost (around April 12) and before the first frost (around October 25). Best results when soil holds above 50°F.
What growing zone is Franklin County County, for Cosmos?
Franklin County County sits in USDA Zone 6b. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Franklin County County's climate?
Yes — Cosmos grows well in Franklin County County's temperate climate. Franklin County County averages a 196-day frost-free season, with last frost around April 12 and first frost around October 25.
Your Franklin County Garden Planner — Free
A 22-page printable planner built for Franklin County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.