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When to plant Zinnia in Colbert County, AL

Colbert County's climate puts the Zinnia spring window between March 30 and April 20. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Zinnia in Colbert County, AL

Colbert County, Alabama Zone 8a June

June in Colbert County, Alabama — your action list

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Colbert County, Alabama.

Avg. last frost April 6
Avg. first frost October 28
Soil temp (4") 80°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Harvest zinnia as they ripen

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

Before July arrives, get these ready
  • First harvests: zinnia

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Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Colbert County, Alabama is in USDA Zone 8a. The average last spring frost is April 6 and the first fall frost is October 28, giving you a growing season of approximately 205 days.

At an elevation of 380 feet, Colbert County receives approximately 50.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89°F, providing good warmth for Zinnia during the growing season. Clay soil retains moisture well for Zinnia, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Zinnia root diseases.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Colbert County, AL (Zone 8a) Long season
205 days
Last Spring Frost April 6
205 growing days
First Fall Frost October 28

Colbert County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.2

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (3 days to spare)
Start indoors: Feb 28 Transplant: Mar 21 🌸 Bloom: May 30 – Oct 17
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 9 Transplant: Mar 30 🌸 Bloom: Jun 8 – Oct 26
Safe Start (90%) ✓ Fits season (10 days to spare)
Start indoors: Mar 21 Transplant: Apr 11 🌸 Bloom: Jun 20 – Nov 7

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 Colbert County

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

Soil pH

Your soil pH (5.5–6.2) is within Zinnia's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Zinnia.

How to Plant Zinnia

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

Succession Planting Zinnia

4
successive plantings in your 205-day season

Sow every 6.9 weeks. Last sowing by Aug 19 to harvest before frost.

Zinnia 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 Zinnia

Zinnia 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 Zinnia Needs Rainfall You Supplement Action
Jan 4.2" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 5.1" 0" ✅ Rainfall sufficient
Jul 2.2" 5.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.7" 0" ✅ Rainfall sufficient
Nov 4.2" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Colbert County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Zinnia 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.

Zinnia needs ~1,089 GDD — county provides 3,433 GDD Excellent fit

Zinnia Planting Timeline — Colbert County, AL

Zinnia Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors March 30 Mar 30 – Apr 13
Direct Sow March 30 Mar 30 – Apr 20
Bloom June 8 Jun 8 – Oct 26

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

Month-by-Month Timeline

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

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

205 days in Colbert County

Growing Tips for Zinnia in Colbert County

Direct sow Zinnia outdoors after April 06 in Colbert County when soil has warmed and frost danger has passed.

With Colbert County's clay soil (34% clay), work in 3-4 inches of compost before planting Zinnia. Avoid tilling when soil is wet to prevent compaction.

Common pests for Zinnia 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 when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Colbert County, AL?

Colbert County is in Zone 8a with an average last frost of April 6. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Colbert County, AL?

Colbert County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is April 6 and first fall frost is October 28.

When should I plant Zinnia in Colbert County, AL?

In Colbert County, AL, plant Zinnia after the last frost (around April 6) and before the first frost (around October 28). Best results when soil holds above 50°F.

What growing zone is Colbert County, AL for Zinnia?

Colbert County sits in USDA Zone 8a. Zinnia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zinnia grow in Colbert County's climate?

Yes — Zinnia grows well in Colbert County's temperate climate. Colbert County averages a 205-day frost-free season, with last frost around April 6 and first frost around October 28.

🌱

Your Colbert County Garden Planner — Free

A 22-page printable planner built for Colbert County (Zone 8a). 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 Colbert County, AL. 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.