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When to plant Black-eyed Susan in Marengo County County,

Plant Black-eyed Susan in Marengo County County after March 13; the prime window is February 27–March 20.

When to Plant Black-eyed Susan in Marengo County, AL

Marengo County, Alabama Zone 8b June

What to do in June

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

Avg. last frost March 13
Avg. first frost November 13
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Bring in the black-eyed susan

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

Before July arrives, get these ready
  • First harvests: black-eyed susan

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Rudbeckia hirta (Black-eyed Susan) is one of the most recognizable and adaptable native wildflowers in North America. Its bright golden-yellow daisy petals radiate from a dark brown central cone, providing months of color from midsummer into fall. Technically a short-lived perennial that self-seeds freely — colonies persist indefinitely in the garden — it thrives in poor soils, tolerates drought, and is irresistible to bees, butterflies, and goldfinches.

Marengo County, Alabama is in USDA Zone 8b. The average last spring frost is March 13 and the first fall frost is November 13, giving you a growing season of approximately 245 days.

At an elevation of 453 feet, Marengo County receives approximately 59.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Black-eyed Susan during the growing season. Clay soil retains moisture well for Black-eyed Susan, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Black-eyed Susan root diseases.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Marengo County, AL (Zone 8b) Long season
245 days
Last Spring Frost March 13
245 growing days
First Fall Frost November 13
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Marengo County Soil Profile

Soil Type

Clay Loam

Soil pH

5.2-6.7

Drainage

Well Drained

Black-eyed Susan Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Jan 9 Transplant: Mar 6 🌸 Bloom: May 15 – Oct 9
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Jan 16 Transplant: Mar 13 🌸 Bloom: May 22 – Oct 16
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Feb 3 Transplant: Mar 31 🌸 Bloom: Jun 9 – 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 Marengo County

How your county's soil matches Black-eyed Susan's growing requirements.

Soil pH

Your soil pH (5.2–6.7) is more acidic than Black-eyed Susan prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Marengo County is excellent for Black-eyed Susan — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Black-eyed Susan.

How to Plant Black-eyed Susan

18"
Between Plants
24"
Between Rows

Succession Planting Black-eyed Susan

4
successive plantings in your 245-day season

Sow every 6.9 weeks. Last sowing by Aug 25 to harvest before frost.

Black-eyed Susan 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 Black-eyed Susan

Black-eyed Susan 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 Black-eyed Susan Needs Rainfall You Supplement Action
Jan 4.5" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 2.2" 5.3" 0" ✅ Rainfall sufficient
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 4.5" 0" ✅ Rainfall sufficient
Jun 2.2" 5.8" 0" ✅ Rainfall sufficient
Jul 2.2" 5.7" 0" ✅ Rainfall sufficient
Aug 2.2" 6.1" 0" ✅ Rainfall sufficient
Sep 2.2" 4.8" 0" ✅ Rainfall sufficient
Oct 2.2" 4.6" 0" ✅ Rainfall sufficient
Nov 2.2" 4.7" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

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

Black-eyed Susan 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.

Black-eyed Susan needs ~1,225 GDD — county provides 4,287 GDD Excellent fit

Black-eyed Susan Planting Timeline — Marengo County, AL

Black-eyed Susan Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors March 13 Mar 13 – Mar 27
Direct Sow February 27 Feb 27 – Mar 20
Bloom May 22 May 22 – Oct 16

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Direct Sow
March Transplant Outdoors Direct Sow
April
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

245 days in Marengo County

Growing Tips for Black-eyed Susan in Marengo County

Direct sow Black-eyed Susan outdoors after March 13 in Marengo County when soil has warmed and frost danger has passed.

With Marengo County's clay soil (30% clay), work in 3-4 inches of compost before planting Black-eyed Susan. Avoid tilling when soil is wet to prevent compaction.

Common pests for Black-eyed Susan in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8–10 weeks before last frost or direct-sow after last frost (needs light to germinate — press seeds onto soil surface, do not cover). Thrives in average to poor soil; rich soil causes floppy stems. Deadhead for extended bloom but leave some seed heads for winter wildlife interest and self-seeding. Although technically short-lived (3–5 years), prolific self-seeding maintains the colony. Year 2+ plants bloom most heavily. Divide every 3 years to maintain vigor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Black-eyed Susan in Marengo County, AL?

Marengo County is in Zone 8b with an average last frost of March 13. Plan your Black-eyed Susan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marengo County, AL?

Marengo County, Alabama is in USDA Hardiness Zone 8b. The average last spring frost is March 13 and first fall frost is November 13.

When should I plant Black-eyed Susan in Marengo County County, ?

In Marengo County County, , plant Black-eyed Susan after the last frost (around March 13) and before the first frost (around November 13). Best results when soil holds above 50°F.

What growing zone is Marengo County County, for Black-eyed Susan?

Marengo County County sits in USDA Zone 8b. Black-eyed Susan grows reliably in zones 3a through 9b, so it's a good fit here.

Can Black-eyed Susan grow in Marengo County County's climate?

Yes — Black-eyed Susan grows well in Marengo County County's temperate climate. Marengo County County averages a 245-day frost-free season, with last frost around March 13 and first frost around November 13.

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Your Marengo County Garden Planner — Free

A 22-page printable planner built for Marengo 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 Marengo 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.