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When to plant Dianthus in Cass County County,

In Zone 6a (Cass County County), direct-sow Dianthus between March 18 and April 8 for spring, after the April 15 last-frost mark.

When to Plant Dianthus in Cass County, IL

Cass County, Illinois Zone 6a June

June in the garden — Cass County, Illinois

Here's what deserves your attention in Cass County, Illinois this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost April 15
Avg. first frost October 16
Soil temp (4") 68°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs
  1. Fire up the seed-starting tray: dianthus

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Pick dianthus

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

July will be here before you know it — start on
  • First harvests: dianthus

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China pinks (Dianthus chinensis) are a reliable cool-season annual offering fringed blooms with a spicy-sweet clove fragrance. They perform best in the cool temperatures of spring and fall, providing vivid color in beds and borders when summer annuals haven't kicked in yet. In warmer zones they are grown as fall–winter–spring annuals. The compact mounding habit and clean foliage make them excellent edging and container plants.

Cass County, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 16, giving you a growing season of approximately 184 days.

At an elevation of 703 feet, Cass County receives approximately 31.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Dianthus to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Cass County, IL (Zone 6a) Moderate season
184 days
Last Spring Frost April 15
184 growing days
First Fall Frost October 16
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Cass County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Dianthus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Start indoors: Feb 12 Transplant: Mar 26 🌸 Bloom: May 14 – Aug 13
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Feb 18 Transplant: Apr 1 🌸 Bloom: May 20 – Aug 19
Safe Start (90%) ✓ Fits season (56 days to spare)
Start indoors: Mar 5 Transplant: Apr 16 🌸 Bloom: Jun 4 – Sep 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 Cass County

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

Soil pH

Your soil pH (6.0–7.2) is within Dianthus's preferred range (6.0–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Dianthus.

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Dianthus.

How to Plant Dianthus

0.1"
Planting Depth
8"
Between Plants
10"
Between Rows

Succession Planting Dianthus

3
successive plantings in your 184-day season

Sow every 6.9 weeks. Last sowing by Jul 28 to harvest before frost.

Dianthus Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 Dianthus

Dianthus 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 Dianthus Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.2" 2.8" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 3.7" 0" ✅ Rainfall sufficient
Jul 2.2" 3.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.8" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.6" 0" ✅ Rainfall sufficient
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Dianthus 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.

Dianthus needs ~858 GDD — county provides 2,254 GDD Excellent fit

Dianthus Planting Timeline — Cass County, IL

Dianthus Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors April 1 Apr 1 – Apr 15
Direct Sow March 18 Mar 18 – Apr 8
Bloom May 20 May 20 – Aug 19

Plant 0.1" deep · 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Bloom
June Bloom
July Bloom
August Bloom
September
October
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 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

184 days in Cass County

Growing Tips for Dianthus in Cass County

Direct sow Dianthus outdoors after April 15 in Cass County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 8–10 weeks before last frost for spring transplants, or direct-sow in early spring as soon as soil can be worked — seeds tolerate light frost. Can also be direct-sown in late summer for fall bloom. Plant in full sun with excellent drainage; poorly drained soil causes crown rot. Deadhead regularly to extend bloom. In zones 8–10, plant as a fall annual for winter– spring color; plants decline in summer heat.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Dianthus in Cass County, IL?

Cass County is in Zone 6a with an average last frost of April 15. Plan your Dianthus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cass County, IL?

Cass County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 16.

When should I plant Dianthus in Cass County, ?

In Cass County, , plant Dianthus after the last frost (around April 15) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Cass County, for Dianthus?

Cass County sits in USDA Zone 6a. Dianthus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Dianthus grow in Cass County's climate?

Yes — Dianthus grows well in Cass County's temperate climate. Cass County averages a 184-day frost-free season, with last frost around April 15 and first frost around October 16.

🌱

Your Cass County Garden Planner — Free

A 22-page printable planner built for Cass County (Zone 6a). 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 Cass County, IL. 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.