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When to plant Cosmos in Bath County County,

The best window to plant Cosmos in Bath County County, is April 16–May 7, when soil warms to 50°F. Last frost typically hits April 16; first frost October 24.

When to Plant Cosmos in Bath County, KY

Bath County, Kentucky Zone 6b June

June to-do list for Bath County, Kentucky

We've pulled the most time-sensitive tasks for Bath County, Kentucky this June and put them front and centre. Tackle them in order.

Avg. last frost April 16
Avg. first frost October 24
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Basket week: cosmos

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of July
  • First harvests: cosmos

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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.

Bath County, Kentucky is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 24, giving you a growing season of approximately 191 days.

At an elevation of 2,458 feet, Bath County receives approximately 43.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Cosmos during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Bath County, KY (Zone 6b) Moderate season
191 days
Last Spring Frost April 16
191 growing days
First Fall Frost October 24

Bath County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Mar 13 Transplant: Apr 10 🌸 Bloom: Jun 19 – Oct 2
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Mar 19 Transplant: Apr 16 🌸 Bloom: Jun 25 – Oct 8
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Apr 4 Transplant: May 2 🌸 Bloom: Jul 11 – Oct 24

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 Bath County

How your county's soil matches Cosmos's growing requirements.

Soil pH

Your soil pH (5.4–7.0) overlaps with Cosmos's range (6.0–8.0), though not a perfect match.

Soil Texture

The silt loam soil in Bath County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Cosmos.

How to Plant Cosmos

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Cosmos

3
successive plantings in your 191-day season

Sow every 6.9 weeks. Last sowing by Jul 26 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 3.4" 0" ❄️ Dormant
Feb 3.2" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.3" 0" ✅ Rainfall sufficient
Jul 2.2" 4.2" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.2" 0" ✅ Rainfall sufficient
Nov 2.8" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Bath 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 needs ~1,256 GDD — county provides 3,199 GDD Excellent fit

Cosmos Planting Timeline — Bath County, KY

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 16 Apr 16 – May 7
Bloom June 25 Jun 25 – Oct 8

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors 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

191 days in Bath County

Growing Tips for Cosmos in Bath County

Direct sow Cosmos outdoors after April 16 in Bath 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 →

Frequently Asked Questions

When should I plant Cosmos in Bath County, KY?

Bath County is in Zone 6b with an average last frost of April 16. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bath County, KY?

Bath County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 24.

When should I plant Cosmos in Bath County County, ?

In Bath County County, , plant Cosmos after the last frost (around April 16) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Bath County County, for Cosmos?

Bath 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 Bath County County's climate?

Yes — Cosmos grows well in Bath County County's temperate climate. Bath County County averages a 191-day frost-free season, with last frost around April 16 and first frost around October 24.

🌱

Your Bath County Garden Planner — Free

A 22-page printable planner built for Bath 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Bath County, KY. 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.