Blog

When to plant Cosmos in Howard County, MO

The best window to plant Cosmos in Howard County, is April 13–May 4, when soil warms to 50°F. Last frost typically hits April 13; first frost October 24.

When to Plant Cosmos in Howard County, MO

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.

Howard County, Missouri is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.

At an elevation of 945 feet, Howard County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Cosmos during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Howard County, MO (Zone 6b) Moderate season
194 days
Last Spring Frost April 13
194 growing days
First Fall Frost October 24

Howard County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Cosmos Planting Timeline — Howard County, MO

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow April 13 Apr 13 – May 4
Bloom June 22 Jun 22 – Oct 5

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

Month-by-Month Timeline

MonthActivities
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

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in Howard County

Growing Tips for Howard 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 Howard County, MO?

Howard County is in Zone 6b with an average last frost of April 13. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Howard County, MO?

Howard County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 24.

When should I plant Cosmos in Howard County, MO?

In Howard County, MO, plant Cosmos after the last frost (around April 13) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Howard County, MO for Cosmos?

Howard 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 Howard County's climate?

Yes — Cosmos grows well in Howard County's temperate climate. Howard County averages a 194-day frost-free season, with last frost around April 13 and first frost around October 24.

🌱

Your Howard County Garden Planner — Free

A 22-page printable planner built for Howard 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.

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 Howard County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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