Blog

When to plant Dianthus in Union County, IL

Dianthus planted in Union County between March 6 and March 27 matures in 60–80 days — well before the October 21 first frost.

When to Plant Dianthus in Union County, IL

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.

Union County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.

At an elevation of 1,017 feet, Union County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Dianthus during the growing season.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Union County, IL (Zone 7a) Moderate season
194 days
Last Spring Frost April 10
194 growing days
First Fall Frost October 21

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Dianthus Planting Timeline — Union County, IL

Dianthus Planting Calendar

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors March 20 Mar 20 – Apr 3
Direct Sow March 6 Mar 6 – Mar 27
Bloom May 8 May 8 – Aug 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Union County

Growing Tips for Union County

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 Union County, IL?

Union County is in Zone 7a with an average last frost of April 10. Plan your Dianthus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, IL?

Union County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 21.

When should I plant Dianthus in Union County, IL?

In Union County, IL, plant Dianthus after the last frost (around April 10) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Union County, IL for Dianthus?

Union County sits in USDA Zone 7a. Dianthus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Dianthus grow in Union County's climate?

Yes — Dianthus grows well in Union County's temperate climate. Union County averages a 194-day frost-free season, with last frost around April 10 and first frost around October 21.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Union County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.