When to plant Cosmos in Dent County, MO
For Dent County, gardeners: plant Cosmos April 10 through May 1 once soil reads 50°F.
When to Plant Cosmos in Dent County, MO
What to do in June
We've pulled the most time-sensitive tasks for Dent County, Missouri this June and put them front and centre. Tackle them in order.
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It's harvest week for cosmos
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
A few tasks this June that'll pay off in 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.
Dent County, Missouri is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 27, giving you a growing season of approximately 200 days.
At an elevation of 774 feet, Dent County receives approximately 31.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Cosmos during the growing season.
Dent County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
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 Dent County
How your county's soil matches Cosmos's growing requirements.
Soil pH
Your soil pH (5.5–6.7) overlaps with Cosmos's range (6.0–8.0), though not a perfect match.
Soil Texture
The silt loam soil in Dent County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Cosmos.
How to Plant Cosmos
Succession Planting Cosmos
Sow every 6.9 weeks. Last sowing by Jul 29 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Dent 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 — Dent County, MO
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Direct Sow | April 10 | Apr 10 – May 1 |
| Bloom | June 19 | Jun 19 – Oct 2 |
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: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
200 days in Dent County
Growing Tips for Cosmos in Dent County
Direct sow Cosmos outdoors after April 10 in Dent 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.
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 Dent County, MO?
Dent County is in Zone 6b with an average last frost of April 10. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dent County, MO?
Dent County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 27.
When should I plant Cosmos in Dent County, MO?
In Dent County, MO, plant Cosmos after the last frost (around April 10) and before the first frost (around October 27). Best results when soil holds above 50°F.
What growing zone is Dent County, MO for Cosmos?
Dent 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 Dent County's climate?
Yes — Cosmos grows well in Dent County's temperate climate. Dent County averages a 200-day frost-free season, with last frost around April 10 and first frost around October 27.
Your Dent County Garden Planner — Free
A 22-page printable planner built for Dent 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.