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

Aim to plant Black-eyed Susan in Washington County County on or after April 12; the window stays open through May 3. Washington County County's 191-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Black-eyed Susan in Washington County, IN

Washington County, Indiana Zone 6b June

This month in Washington County, Indiana

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 12
Avg. first frost October 20
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Start black-eyed susan under lights

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

July will be here before you know it — start on
  • 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.

Washington County, Indiana is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 20, giving you a growing season of approximately 191 days.

At an elevation of 540 feet, Washington County receives approximately 32.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Black-eyed Susan during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Washington County, IN (Zone 6b) Moderate season
191 days
Last Spring Frost April 12
191 growing days
First Fall Frost October 20

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.1

Drainage

Well Drained

Black-eyed Susan Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 4 Transplant: Apr 15 🌸 Bloom: Jul 1 – Oct 21
Recommended (50%) ✗ May not fit
Start indoors: Feb 8 Transplant: Apr 19 🌸 Bloom: Jul 5 – Oct 25
Safe Start (90%) ✗ May not fit
Start indoors: Feb 26 Transplant: May 7 🌸 Bloom: Jul 23 – Nov 12

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 Washington County

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

Soil pH

Your soil pH (6.3–7.1) overlaps with Black-eyed Susan's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Black-eyed Susan will thrive.

How to Plant Black-eyed Susan

18"
Between Plants
24"
Between Rows

Succession Planting Black-eyed Susan

3
successive plantings in your 191-day season

Sow every 6.9 weeks. Last sowing by Aug 01 to harvest before frost.

Black-eyed Susan Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 1.5" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.2" 3" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 3.8" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 3.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.6" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Washington 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 ~1,015 GDD — county provides 2,769 GDD Excellent fit

Black-eyed Susan Planting Timeline — Washington County, IN

Black-eyed Susan Planting Calendar

Activity When Date Range
Start Indoors February 8 Feb 8 – Feb 22
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 12 Apr 12 – May 3
Bloom July 5 Jul 5 – Oct 25

· 18" apart · Rows 24" apart

Month-by-Month Timeline

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

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

191 days in Washington County

Growing Tips for Black-eyed Susan in Washington County

Direct sow Black-eyed Susan outdoors after April 12 in Washington County when soil has warmed and frost danger has passed.

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 Washington County, IN?

Washington County is in Zone 6b with an average last frost of April 12. Plan your Black-eyed Susan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, IN?

Washington County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 20.

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

In Washington County County, , plant Black-eyed Susan after the last frost (around April 12) and before the first frost (around October 20). Best results when soil holds above 50°F.

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

Washington County County sits in USDA Zone 6b. Black-eyed Susan grows reliably in zones 3a through 9b, so it's a good fit here.

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

Yes — Black-eyed Susan grows well in Washington County County's temperate climate. Washington County County averages a 191-day frost-free season, with last frost around April 12 and first frost around October 20.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington 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 Washington County, IN. 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.