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When to plant Cosmos in Kellerman, AL

Kellerman's spring Cosmos window runs March 1 through March 22. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Cosmos in Kellerman, AL

Tuscaloosa County, Alabama Zone 8b July

This month in Tuscaloosa County, Alabama

Welcome to July in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 22
Avg. first frost November 9
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Pick cosmos

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to August
  • 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.

Kellerman, Alabama is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 9, giving you a growing season of approximately 232 days.

At an elevation of 436 feet, Tuscaloosa County receives approximately 52.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94°F, providing good warmth for Cosmos during the growing season. Clay soil retains moisture well for Cosmos, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Kellerman, AL (Zone 8b) Long season
232 days
Last Spring Frost March 22
232 growing days
First Fall Frost November 9

Kellerman Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.2

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Feb 13 Transplant: Feb 20 🌸 Bloom: May 1 – Oct 2
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Feb 22 Transplant: Mar 1 🌸 Bloom: May 10 – Oct 11
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Mar 17 Transplant: Mar 24 🌸 Bloom: Jun 2 – Nov 3

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 Kellerman

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

Soil pH

Your soil pH (5.5–6.2) is more acidic than Cosmos prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Cosmos.

How to Plant Cosmos

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

Succession Planting Cosmos

4
successive plantings in your 232-day season

Sow every 6.9 weeks. Last sowing by Aug 11 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
Drought risk

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 4.5" 0" ❄️ Dormant
Feb 4.7" 0" ❄️ Dormant
Mar 2.2" 5.2" 0" ✅ Rainfall sufficient
Apr 2.2" 4.1" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.7" 0" ✅ Rainfall sufficient
Jul 2.2" 5.3" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 4.5" 0" ✅ Rainfall sufficient
Dec 4.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tuscaloosa 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 ~1,538 GDD — county provides 4,756 GDD Excellent fit

Cosmos Planting Timeline — Kellerman, AL

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors March 1 Mar 1 – Mar 15
Direct Sow March 1 Mar 1 – Mar 22
Bloom May 10 May 10 – Oct 11

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April
May Bloom
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: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

232 days in Tuscaloosa County

Growing Tips for Cosmos in Kellerman

Direct sow Cosmos outdoors after March 22 in Tuscaloosa County when soil has warmed and frost danger has passed.

With Tuscaloosa County's clay soil (33% clay), work in 3-4 inches of compost before planting Cosmos. Avoid tilling when soil is wet to prevent compaction.

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 →

When should I plant Cosmos in Kellerman, AL?

In Kellerman, AL, plant Cosmos after the last frost (around March 22) and before the first frost (around November 9). Best results when soil holds above 50°F.

What growing zone is Kellerman, AL for Cosmos?

Kellerman sits in USDA Zone 8b. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.

Can Cosmos grow in Kellerman's climate?

Yes — Cosmos grows well in Kellerman's temperate climate. Kellerman averages a 232-day frost-free season, with last frost around March 22 and first frost around November 9.

🌱

Your Tuscaloosa County Garden Planner — Free

A 22-page printable planner built for Tuscaloosa County (Zone 8b). 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 Tuscaloosa County, AL. Local conditions may vary. Last updated: July 2026.